Neon Tetra

Paracheirodon innesiNeon Tetra

Scientific name:                 Paracheirodon innesi    
Common name:                Neon Tetra
Max. size:                           2.2 cm / 0.85 inches
pH range:                          5.0 – 7.0
dH range:                           1 – 2
Temperature range:         20 – 26°C / 68 – 80°F

The Neon Tetra is an extremely popular aquarium fish. It is sturdy and inexpensive and is often one of the first fish species purchased by beginner aquarists. A shoal of brightly decorated Neon Tetras will add colour as well as activity to the aquarium. Since the Neon Tetras stay quite small and have a peaceful temperament, they are often found in small community aquariums.

Neon Tetra classification:

The Neon tetras belongs to the genus Paracheirodon in the family Characidae. This makes it closely related to other popular aquarium fishes like the Cardinal tetra (Paracheirodon axelrodi) and the Green Neon tetra (Paracheirodon simulans). The less commonly kept Black Neon tetra (Hyphessobrycon herbertaxelrodi)is however a more distant relative since it belongs to another genus within the family Characidae; the genus Hyphessobrycon.
All members of the genus Paracheirodon are native to the Neotropic ecozone in northern South America and their bodies are decorated with a characteristic sparkling blue lateral line. They are often kept together in planted community aquariums with soft, acidic waters and tropical water temperatures.

Neon Tetras in the aquarium trade

The Neon tetra is an extremely popular aquarium fish, especially among beginner aquarists. Over 1.5 million Neon tetras are imported to the United States alone – each month! It can be tricky to breed in captivity for hobby aquarists, but professional breeders that produce immense quantities of Neon tetra exist in several countries world wide. If you purchase Neon tetras in the United States, the chance is high that they hail from Thailand, Singapore or Hong Kong. Wild caught Neon tetras from Brazil, Colombia and Peru are however also still available in the trade.

Neon Tetra habitat and range:

The Neon Tetra is a pelagic freshwater fish native to tropical parts of northern South America. The Neon tetra originates from westerns Brazil, south-eastern Colombia and eastern Peru and wild Neon Tetras can be found in the headwaters of the River Amazon, Tiger, Napo and Yarapa. It is present in both blackwater and clearwater stream tributaries. You can however not find Neon tetras in the whitewater rivers that run from the Andes. The Neon Tetras have bright colours and an iridescent stripe in order to be visible in dark blackwaters.

A lot of Neon Tetras are caught from Rio Solimões. Rio Solimões is a name attributed to an upstream part of the great River Amazon; a part that starts at the border of Brazil and Peru and ends when the river converges with Rio Negro. (In Brazil, the name Rio Solimões is sometimes used even further upstream, but the name Rio Marañón is more common for those parts.)

The South American blackwater and clearwater streams and rivers have very soft and somewhat acidic water. The flow through tropical regions and the water temperature stays around 20 – 26° C (), sometimes higher. The commercial bred Neon Tetras have often been adapted to conditions that are very different from those found in their native habitat.

Today, an introduced population of Neon Tetra is established in Singapore.

Neon tetra description:

Just like the other tetra species, the Neon tetra has a spindle shaped body and a blunt nose. A glistering blue line runs along each side of the body, from the nose and all the way to the adipose fin. The Neon tetra is also decorated with a red stripe that runs from the middle of the body to the base of the caudal fin. The side over the blue stripe is of a dark olive green shade. The belly is of a silvery colour and the anal fin is nearly transparent.

During the night, when the fish is resting in a sheltered place, the sparkling colours will be turned off and the fish will look dim. If you quickly turn on the lights in the aquarium after a longer period of complete darkness, you might not notice your Neon Tetras at first. If the colouration continues to be dull even after some time in the light, your tetras might be ill or stressed. You might also be keeping them on an inadequate diet.

The Neon Tetra is often mixed up with the Cardinal Tetra, since they both feature striking red and blue stripes. The Cardinal Tetra is even sometimes referred to as “Red Neon Tetra” in everyday language, even though it is in fact a separate species and not a colour variation of the Neon Tetra. Distinguishing these two species from each other is however not difficult at all if you know what to look for. Under the sparkling blue stripe, you will see a red lateral stripe in both species. If this red strip ends roughly halfway from the nose of the fish, you are looking at a Neon Tetra. If the striping instead continuous much longer, you are looking at a Cardinal Tetra. The name Cardinal Tetra is derived from the long, red robes worn by cardinals and these robes do not end half-way.

Neon Tetra behaviour and suitable tank mates:

The Neon Tetra is a peaceful fish that is often kept in community aquariums with other non-aggressive fish species of roughly the same size. Neon tetras look very beautiful when combined with other tetra species, but they can be combined with fishes from a broad range of other families as well. Keep in mind that most tetra species are less robust than the Neon tetras when it comes to water conditions. Neon tetras should naturally never be combined with larger fishes that will consider them prey, or aggressive fish species that will bully them.

The Neon Tetra is a shoaling species and you should always keep at least five Neon Tetras together, preferably more. A Neon Tetra that is kept alone will be much stressed and spend most if its time hiding. The stress can also weaken its immune system and make it more susceptible to illness. A large group of Neon Tetras are naturally also much more beautiful to watch in the aquarium and you will be able to see a much broader range of natural Neon Tetra behaviors. When kept in a shoal, Neon tetras are active creatures and they will spend most of their time in the middle to lower strata of the aquarium. Neon Tetras are known to sometimes shoal together with the closely related Cardinal Tetras.

Neon tetras can reach an age of 10 years or more in captivity, but most Neon Tetras have considerably a shorter life span than this.

Neon Tetra setup:

Try to mimic the natural Neon Tetra habitat when you set up the aquarium. The River Amazon and its tributaries are filled with densely grown plant life and the rivers and streams are shaded by jungle vegetation. Your Neon Tetras will therefore appreciate a planted aquarium with plenty of hiding spots. There should also be an open area for swimming. The light should be subdued; ideally use floating plants to make the aquarium a little darker for your tetras. The bottom should preferably consist of a dark substrate. Many aquarists cover the back and sides of the aquarium with dark tissue to make the aquarium darker and bring out the contrasting colours in their Neon Tetras. The recommended minimum aquarium size is 60 cm (24 inches).

Neon Tetra care:

Captive bred Neon Tetras are often adapted to conditions that differ a lot from those found in the original Neon Tetra habitat. Wild Neon Tetras inhabit very soft and slightly acidic waters in tropical regions of South America where the water temperature usually stays between 20 and 26° C (68 and 80° F). Rainforest rivers and streams are frequently replenished by soft downpour and frequent water changes are therefore recommended in the aquarium.

Generally speaking, the recommended pH range for Neon Tetras is 5.0 – 7.0 and the recommended dH range 1-2. If your Neon Tetras have been raised in an aquarium with different water chemistry, a rapid change can however harm them. Neon Tetras should therefore always be gradually adjusted to new conditions.

Since Neon Tetras are so popular, the Neon Tetra breeding business has naturally attracted not only dedicated Neon Tetra breeders but also irresponsible ones that do not really care about creating high quality fish. A lot of the commercially bred Neon Tetras will end up in aquariums kept by novice aquarists that will assume that they have done something wrong when their Neon Tetras die shortly after being purchased. Selling low quality Neon Tetras is therefore not really risky; it can even be a good for business since many inexperienced aquarists will return to the store for more and more Neon Tetras as the old ones succumb. This is naturally a problem since you might get really fragile Neon Tetras from your local pet shop that will not adapt well to new conditions. It is therefore always recommended to provide your Neon Tetras with plenty of time to acclimatize themselves when you introduce them to their new home. Carefully monitor your Neon Tetras and quickly remove dead specimens before they get a chance to contaminate the water.

It is perfectly natural for a Neon Tetra to look dull during the night since it turns off its iridescent colours. In the morning, it can need a little time to recover. If your Neon Tetra continues to show dull colours throughout the day you should however try to figure out why, since it is a warning sign that your fish is not doing well. A Neon Tetra that is kept alone instead of in a shoal can loose its iridescent colours, and the same is true for tetras that become stressed by the presence of bullying fish or that are kept in a barren aquarium without any good hiding spots. It can also be a sign of disease, poor water quality or malnutrition.

Neon Tetra feeding:

Wild Neon Tetras are omnivore and feed on plant matter as well as on crustaceans, worms and small insects. They are not fuzzy eaters in the aquarium and will accept most food types, including flake food, frozen food and freeze-dried food. Keep them on a varied diet to prevent malnutrition. You can for instance use a high-quality tropical flake food as a base and supplement it will occasional treats in the form of daphnia, brine shrimp, bloodworms or similar.

Neon Tetra disease:

Neon Tetras are susceptible to the Neon Tetra disease. There is still no available cure for this disease and it will often kill the fish. Neon Tetra disease is caused by a sporozoan named Pleistophora hyphessobryconis. The disease is therefore also known as “Pleistophora”.

During the initial stage of Neon Tetra disease, parasite spores enter the Neon tetra. Common symptoms include restlessness and dull colouration. As the disease proceeds, cyst will develop and the fish body can become lumpy. The Neon Tetra will often have trouble swimming and towards the final stages of the disease the spine can become curved. The weakened fish is also susceptible to secondary infections.

As mentioned above, these is still no cure for Neon Tetra disease and trying to prevent the parasite from entering your aquarium in the first place is therefore the best course of action. The parasite is typically introduced via live food or newly purchased fish. By cultivating your own live food you will gain a greater control over what you put in your aquarium. Brine shrimp is for instance very easy and hassle-free to cultivate at home. When you purchase new fish, you should ideally keep them quarantined in a separate aquarium and look out for signs of illness. In the aquarium, fish often catch the disease when they eat dead fish. Removing sick and dead fish as soon as possible is therefore important. Some aquarists report that using a diatom filter decreases the risk of Neon Tetra disease, but it is only a supplement, not a substitute for the precautions described above. A diatom filter can reduce the amount of free parasites in the water.

There is also a disease known as “false Neon Tetra disease” that is often confused with true Neon Tetra disease. This disease is not caused by a sporozoan; it is caused by bacteria. The symptoms are however very similar and unless you have access to a laboratory it will be virtually impossible for you to tell the difference between the two diseases.

Neon Tetra breeding:

Wild Neon Tetras are highly prolific and have a minimum population doubling time below 15 months. They are egg-scatterers and do not engage in any parental care.

In captivity, Neon tetras are considered quite difficult to spawn, especially among hobby aquarists since it can be hard to achieve perfect water conditions. A majority of the Neon Tetras found in pet shops are therefore wild caught or commercially bred by large Neon Tetra breeding companies. It is possible for Neon Tetras to spawn every two weeks.

Sexing Neon Tetras can be hard, but the female usually have a bigger and rounder belly than the male. The blue line will be straighter in males, while the round female body creates the impression of a bent blue line. When she is ready to breed, her body will become very broad since she is filled with eggs.

If you want to breed Neon Tetras, you should ideally set up a separate breeding aquarium from which the parents can be removed as soon as the eggs have been fertilized. To reduce the risk of illness in eggs or fry, you can sterilize all items that you place in the aquarium.  The breeding aquarium should be equipped with a lid, since Neon Tetras can jump really high during the breeding period. The bottom of the aquarium should ideally be covered in 2-3 inches of rock. Include fine textured aquatic plants in the set up. Keep the water temperature below 24° C (75° F). The hardness should always be below 4 degrees, ideally in the dH 1-2 range.

If you want to obtain high-quality fry, it is important to only let high-quality adult fish breed. Old or unhealthy fish should not be bred. Place a pair of Neon Tetras in the breeding aquarium and feed them plenty of live food to induce spawning. Mosquito larvae are used by many professional breeders. Some breeders will let the nitrate level rise quite high in the breeding aquarium before they change at least 50 percent of the water since this sometimes induces spawning. The rapid decrease of soluble waste is a way of mimicking a fresh, replenishing rain. The breeding aquarium should be dark at first, and you can then gradually increase the lighting until the couple spawns. (Neon Tetra eggs are a bit light sensitive so it is important to limit the amount of light after spawning.)

Neon tetras will usually spawn during early morning and the parent fish should be removed from the breeding aquarium as soon as possible after fertilization since they will not hesitate to eat their own offspring. In aquariums, a normal batch will consists of approximately 130 eggs but only a smaller number will turn into fry. Neon Tetras that spawn in aquariums are usually not very prolific, so do not expect more than 40-50 fry even from a good spawning.

Neon tetra eggs are somewhat adhesive and will often stick to the surface of aquatic plants. They are nearly transparent when they have just been released, and will hatch after 22-30 hours. It will take the fry 3-4 days to become free swimming.

Neon Tetra fry are very small and must be provided with miniscule food, such as infusoria, rotifers or egg yolk. After 1-4 weeks, they will be large enough to eat newly hatched brine shrimp. Large fry will appreciate shaved cattle liver. When the fry is roughly one month old, they will start displaying their adult colouration.

92 thoughts on “Neon Tetra

  1. Hi new fish owner here. I have 3 glo, 1 betta, 1 neon tetra, and 2 catydora. The glo are super active as are the catfish, but the tetra and betta seem lonley. Not too worried about the betta aside from feeding. The tetra on the other hand kinda just floats mid tank not really swimming much. Also kind of twitches often. Doesn’t seem good.

    1. Neon Tetra’s are shoaling fish so are better in groups rather than individually. Get a few more up to about 6-7 and he’ll probably pick

  2. I have a problem with nitrates and nitrites,I have done everything by the book and reduced the amount of food I am feeding my fish to ensure non left over. I am at a loss as to what to do so I can balance my tank.
    Please can you help.My fish seem happy enough at the moment.

    1. What is your problem with nitrates/nitrites? Are the numbers too high? If they’re too high how do you know? If your using test kits and they’re old they can sometimes give incorrect readings likewise those dip stick test kits are crap too. What is your ammonia level like when a tank is fully cycled you should see near zero ammonia and nitrites and the only thing that should be left is nitrate at the end of the cycle. You can minimize / reduce all of these factors quite easily by over / more filtration and/or live plants!
      Do you have sufficient filtration for the size of the tank, the stocking levels? Do you have good water movement through the filter? When you clean the filter do you make sure you do it properly or do you clean it in tap water thus resetting the cycle? Do you clean the tank substrate gravel/sand etc get all the detritus out?

      Lots of questions and variables all need consideration when looking at whats wrong with a tank cycle and its balance. Its always easier to give advice and indeed for you to work out whats wrong if you have more information.

      1. well my heater is 100w heater which is set on 26 which is the setting I was told to put the heater on but my thermometer use to say 26-27c but now it says its between 30-80c I have a 100 watt filter which I clean under the tap every 2days which is round about the same time I change the water which is every 2 days I don’t ever clean the gravel or sand as im not shore on how to do that as I was told you cant take them out of the tank to clean the whole tank as they well die so ive always just kept them in there while I clean them please if you can help me or advise me on the right track I be great full

        1. If its between 30 and 80 c then I’m surprised all the fish aren’t boiled sounds like the heaters packed up and locked on. Try to keep it stable around 24-25 if you can. Never clean a filter under tap water all that does is kill the bacteria in the filter which is whats keeping your tank clean and fish healthy and as I said in the other comment never clean it more than every 2 weeks (I do mine every 6 months when I notice flow slow down only!) Make sure any filter media is cleaned in old tank water.
          For cleaning the gravel get a gravel vac off ebay they’re like a fiver and there’s plenty of videos on youtube showing you how to use them.

      2. I have been using the dipstick and they say I have nitrates and nitrates even when I have done a larger water change than necessary. The filter is a Aqua one maxi and my tank is only 38liters so adequate and I wash the filter in the water I have removed. I only have 2 tetra and one angel fish as the others died shortly after I put them in 5 weeks ago and I have never got the water right to add anymore.
        I did have glass beads in the tank as that is what it came with but found it difficult to clean so got rid last Friday and put in gravel.
        I have been adding An quell plus but that changed zilch. I can’t test for amonia so don’t know that answer.
        Thanks for your help.

        1. Had my water tested today no amonia just nitrates and nitrites. Done another 20 percent water change and cleaned filter so hopefully it will settle.

        2. Right the dipstick things are useless, at 38 liters it’ll be a knife edge for keeping it stable (small tanks are hard). Clean the filter less often no more than once every 2 weeks give it more time to settle and make sure you treat any new water you put in before you add it to the tank. Keep water changes small for such a small tank perhaps just a 2 liter change once a week will do it. See if it improves the readings.

          1. OK thank you I have been changing the water every week at probably 25 to 30 percent. I did notice this week that the filter was very dirty but presume this was due to me adding in new stones.
            I was wondering if I should feed the fish alternate days and see if this settles things but feel very cruel doing this as all three fish seem eager to eat.

          2. I only feed my tanks twice a week but I feed heavy the long period makes sure there’s no waste. If you want to feed often that’s fine but a tiny tiny amount just a small pinch is more than enough if using flake

  3. hay dave just question do you have to have tank ornaments for your fish tank the reason i am asking is that i didn’t have any ornaments part from a rock and my fish i brought have been fine with just having a rock in the tank but then i i desided to put some fake plates in there as it looked to bare and i washed them before putting them in the tank and then that same night i lost half of the fish i did have so now im stuck of what to do now can you help as i would like to buy some new fish to compensate for the half i lost but don’t want the same thing happening

    1. Fish don’t need ornaments that’s purely for the humans. Certain fish like plecs like wood in the tanks to chew on but neons etc don’t need anything. Putting real plants in is often good though helps keep the tank stable.

      1. hay dave my pet shop has red tail sharks I brought one two weeks ago which was ok whenthe owner of the pet shop sold it to me but when I got it home I fond it dead in the bag it was in so I went back told him about it but he said s it one of those things that happen he just got some in today so I got another red tail shark today but the same thing is happening and don’t know why I keep finding that they have dead as soon as I get them home cant under stand

        1. Fish are probably in poor health to start with sounds like a bad fish shop to me. A little car journey probably shocks them into dying on journey home.
          Also don’t get a detailed shark its far too big a fish for your tank

    1. Too much light. Turn your lights down/off this is especially an issue if you have artificial plants rather than real plants. Green water is a sign your tank isn’t in balance and the excess nutrients etc are using the excess light to create plankton/algae. Simple solution do lots of water changes and only put your tank lights on for a couple of hours a day. Also if the tank is near direct light source ie: a window. move it away from the window so its in a light but shaded corner not getting direct light.

  4. I bought one angel fish and 6 neon fish ,four of the neon fish died within 48 hours leaving me with just the 2 neon and one angel. The fish are now over a week old in the tank and seem to be fine. My problem is the Angel fish is so greedy he does not let the other two get a look in and they will not come to the top of the tank. I have seen them both get small bits of food the angel misses. Will they be OK? .

    1. They should be fine you could try feeding a little extra so there’s more left over by the angel for the neons but thats up to you

      1. Thank you Dave.I would like to add some more fish,my tank ia about 30 lts what do you suggest.

  5. hay dave need your help my angel fish use to come to the top of the suffice to feed but now he just sits at the bottom swimming around and not bothering wth the food is it because its on its own please help

    1. Could just be him settling in to a new tank. Make sure you don’t over feed them. Check your water parameters now you have fish in it it should begin its cycle properly keep an eye in it you may need to start to do lots of little water changes

      1. I did a water change yesterday the parameters are ok and ive been feeding the small a mount as it said on the tropical fish food flakes and it said to do that twice daily is that to much food and I have anther question I have 8 guppies males and females what does it mean when there are 2 males chasing on female as I don’t know

        1. I feed my tanks once every 2 days so that’s a guideline. Once a day is more than enough twice probably too much. 2 males are chasing females as guppies breed like rabbits you’ll have baby guppies in days then the angel fish can go ahead and eat all the babies 🙂 be careful male guppies can over harass the females and end up killing them especially if you have more males than females. Better to keep 2 females to 1 male to spread the aggression around

          1. I know I change the water on sunday would it be ok to change the water today and I have 5 males and 3 female guppies

          2. I’d put more females in minimize the abuse from the males allow it to be spread around. Once a week water changes no more than 10% once its settled down so for a tank of your size perhaps one bucket out and one bucket in per week make sure to treat the fresh water with prime or something equivalent.

          3. when it comes to adding some more fish do I have to leave the tank full or do I leave water high enough but not to close to the top as not shore I do have two Zebra Danio in with the guppies and neon’s as well which I purchased the neon’s guppies angelfish and the albino catfish and the 2 Zebra Danio all together I am gonna get some more fish to put in the tank with them I am thinking of buy another angelfish and 1 more Cory cat fish but not shore what else I can put in there with them

          4. Always leave 2-3 weeks between adding more fish let the biological side of the filtration to adjust to the stocking levels. If you add fish too many too fast you can get a cycle spike and kill all of them be slow and patient it’ll pay off in the long run. As for types of fish I like Sword tails and harlequin rasbora’s

          5. hay Dave I need your help as of yesterday I came back from shopping and I went to feed my fish and I notice there was a baby neon in there but don’t know how long its been in there for as you can see its fall body but its still small but im a bit worried as its swimming around ok but its always on it side so I quickly put the 3 in 1 floating breeder tank but I checked the baby neon this morning it still swimming around alright but it still on its side what can I do to help the little guy or girl please help

          6. It’ll be a baby guppy not a baby neon (well it could be a neon but unlikely neons are alot more difficult to breed, guppies on the other hand spit them out in a pint pot.). At the moment it probably looks like 2 eyes a small body and a stub of a tail feed it very small amounts of crushed up flake couple of times a day, and I mean very very small amounts. They grow fairly quick in a week’s time you should be able to tell what it is don’t worry about it swimming weird that’s probably it just struggling in the flow of water in the tank for now. You’ll probably find there’s many more babies in there some where or they’ve been eaten or sucked in to filter.

          7. hay dave ive just borought an silver angelfish to go with my black angel fish but the angelfish i already got keeps bumping the sliver angelfish out the way each time it comes close to him or her is the normal as not shore

          8. They’re just getting used to each other. If its 2 males they’ll always peck at each other unless there’s plenty of tank space. If its a male and a female and they pair up there’s always a little bit of bumping too. I wouldn’t worry too much just keep an eye on it to make sure it doesn’t get out of hand

    2. hay dave it was a neon as I could see its full colour it was blue at the top and I could see a bit of red in its back fin but sadly this morning it passed away mate

  6. I have a 60 litre tropical fish tank its got artificial plants rockery gravel and special fish tank sand im a beginner and im wanting to get neon’s but not shore how many fish I can get in a 60 litre tank the Tempe is 20-26 c

      1. I have 100l filter in the tropical tank and a 100w heater and heater tempter stick which is reading 20 – 26 c is that good filtration for neons and the tank also came with the sand and gravle but not shore wheather neons can live with sand in the tank as well as gravle as im a beginner

        1. They’ll be fine with both sand and gravel either is fine mixing them in kinds pointless unless you can separate them some how with a little wall or something otherwise the sand will all sink to bottom and gravel will sit on top. Don’t go mad with the fish perhaps add just 3 or so at first leave them a week before adding more

          1. thank you dave for your comments they where really helpful is there anything else I need to do to the tank or is two artificial plants and one rockery enough for the neons

          2. Neons are easy fish don’t really need anything much just good clean water and good filtration. After that a tank of warm water and that’s it you can add some real plants in future when you feel confident and when you get really good planted tanks with neons in look great

          3. hi Dave im going to get my neon’s today for my 60litre tank I told you about but im worried as I don’t have a backing cover for the tank and I haven’t put any tap safe in the tank either does this matter or not

          4. Pick up some prime or other water conditioner while your out getting neons put some on and give it a good mix before putting fish in. Remember introduction fish slowly. Tank backing doesn’t matter that’s for benefit of humans not fish

          5. ok dave thank you can you advise me how I slowly introduction the fish to the tank I know I sit the bag on top of the water first but don’t know how long for please help as I am just learning

          6. cause im not just getting 6 neons im get guppys and Cory Catfish for the tank don’t know how many cory catfish I can put in my tank or how many guppys cause im picking them all up today from my local pet shop

          7. Guppies you could do 10-15 they’re similar to neons corys I’d go with 2 perhaps 3 at most.
            You should really drip introduce the fish not bag float as that’s not a particular good way of doing it. Google will give you the answers on how to introduce both fish as I can’t remember if I have an actual article on here about that

          8. hay dave I got my fish today I got neon’s guppies angle fish and a Albino Cory catfish is there any thing i should know about the albino Cory catfish as I know in some albino animals have health issues

          9. Corys are no problem they’re small and easy to keep no major issues as long as your water is good make sure you use food that sinks to bottom for them though algae wafers are good. Assuming you mean angel fish not angle fish 🙂 that’s probably a mistake for such a small tank angels get quite large my biggest is bigger than my hand and they can be quite aggressive / fin nippers especially around fancy fish like guppies

          10. I only brought 10 neon’s 8 guppies 1 angel fish and 1 albino cory catfish and they seem to be doing ok

          11. hi dave just to let you know I got the tank size wrong as I had a someone provtional from pets at home come measure the size of the tank actually holds 120 gallons sorry I gave you the wrong tank size before its the first time id ever measured a tank so im sorry but I have brought 10 neon’s 8 guppies 1 angle fish and 1 albino catfish

          12. If it’s 120 gallons that’s massive sure its not 120 litres? Either way if its that size you can fit loads more I. It

          13. hay dave I have 10 neon’s 8 guppies 1 angelfish and 1 albino catfish what other tropical fish can live with them as I get some more next Thursday

          14. Get another 5 corys they’re great in groups then if you want another 10 neons or guppies if not I like harlequin Rasbora’s

          15. Wouldn’t recommend it silver sharks get big more than anything your tank isn’t big enough for them

  7. To vary the light for tanks put aluminium foil on the glass,this can be adjusted to vary the light.

  8. Brought 6 tetras and 4 have died in the past week. Water tested and is ok. Temp is also fine. Any suggestions what we can do?

    1. Could just be a bad batch unfortunately they’re that heavily farmed and interbred these days you can just get bad fish. Having said that you cannot rule out bad water in the tank, what is your temp and what were your test results ?

  9. Re the comment about losing a Neon Tetra. I bought 6 some months ago and after a couple of weeks could only see 5. I assumed one had died but as small perhaps I couldn’t find evidence of this. I count them daily and still had 5 – until a couple of days ago when I counted 6 again! I don’t know how I missed the other one, even during cleaning the tank and water changes I could only ever see 5 so the person who seems to have lost one, may not have.Give it time and keep checking, it might still be there.

    1. As long as its well filtered and has some real plants in it not fake plants then you can support 10 tetras quite happily

  10. Can my neons eat each other, had 6 fish this morning in my new tank only 5 now.

    1. Yep they can and will most fish will, If one of your fish is weaker / sick the others will nip and eventually kill it usually (especially in the aquarium) then they promptly proceed to eat the body. Check in your plants/gravel/filter inlet/under any decoration etc for the body try to get it out as a rotting corpse can screw up your tank balance badly even with small fish. Look carefully dead neon’s are almost completely white so blend in well with light gravel etc.

  11. I have just bought a 60 litre tank and I am in the process of cycling it with the advice of my local aquatic store. I have 4 danios and 10 neon tetras in the tank. the danios are all over the place and seem to be loving the tank, however the tetras are all hiding at the bottom of the tank at the back. They only come out into view when I feed them. Is this natural or is there something wrong? My tank is at 24 degrees and there is decent waterflow in the tank due to the filter. Am I doing something wrong?

    1. They’ll settle down you are kinda doing something wrong by cycling the tank with large stockings of fish. Please make sure you do regular water changes while cycling otherwise you’ll kill most of your fish

      1. Dave,

        Thanks for getting back to me. I’m cycling the tank as per the recommendations of the shop. However, they did tell me to do regular water changes too. Change 15-20% of the water once a week to start then the same volume once every week to two weeks thereafter. Would you agree with the above or should I change the water more regularly?

        1. Doing a fishy cycle rather than fishless do 10-15% every 2 days for a couple of weeks then do 10-15% once a week after that. Always do weekly changes in small tanks especially in warm weather

          1. Will do. I’ll make sure I keep on top of that. Thank you for the advice and for getting back to me.

            With regards to adding fish to the tank once the cycle is complete, I was thinking about getting 1 male crowntail betta, I red tip shark, either 3 electric blue rams or 5 endler guppies and 4 cherry shrimp or 6 black kuhli loaches. What are your thoughts on that mix of fish?

          2. If you’ve got 4 danios and 10 neons then your pretty much fully stocked for a 60l tank.
            Betta will be bullied and fin nipped by neons they’re quite aggressive.
            Sharks of all types are too big for a tank that size.
            You could perhaps handle 1 or 2 rams but you’ll be doing water changes every couple of days to keep on top of their waste.
            Forget about loaches in a tank that size. Shrimp perhaps OK may get eaten

    1. A nice group of 10 or 12 would be fine in that size tank if you plant it up well they’ll look lovely. May want to consider cardinal neon tetras instead of the ,more common variety

      1. ive never seen angle fish eating guppys. I have 4 large angel fish living with 12 guppys and over 50 neons. my angel fish don’t even bother with the baby fry. as thay know thay got no chance of even out running them. thay say thay will eat anything thay can get in there mouth. I think its rubbish.

  12. Okay so I have three tetras in my tank and one betta fish. I woke up this morning to 5 eggs in the tank and not sure what to do from here?

    1. Highly unlikely they’re Neon tetra eggs more likely snail eggs. Neons are actually blackwater fish so prefer blackwater to breed in unless you’ve deliberately created this environment to breed them in then its unlikely they’ve actually bred.

      See this artical on PFK with regards to some of the hoops that you’d need to jump through to even get Neons to spawn.

      Its due to this complexity I say its more than likely not neon eggs you have but snails.

      1. So where have these snails come from? And are they okay to be in the tank

        Thanks for your reply

        1. Could be anywhere perhaps on a plant bought from a fish shop, or in the water fish came in. Almost all aquatic snails are fine however some can take over if not kept in check.

          Wait and see with the eggs if its fish eggs they’ll probably be around for a fair few days if they’re snail eggs they’ll probably vanish quite quickly.

      2. Dave, please stop spreading false information! Neon tetras are NOT brackish water fish! They are from soft, acidic waters in South America! Putting them in brackish water is a sure way to kill them!

        1. Thanks for spotting the mistake I meant blackwater don’t know what I was thinking when I typed that comment up. I’ve amended it now so it makes more sense.

  13. Having set up my tank and now have 8 tetras ( 4 Neon, 4 Penguin) It’s nice to come here and get some good advice. Something you may be able to help we with is the lighting. The tank has a 15 fluorescent tube (no dimmer switch) but seems a bit bright. Would this be OK if the tank had lots more shaded areas, floating plants etc, or should I install lower powered lighting.
    Thank you for any help you can offer.
    Cheers, John.

    1. Lighting is purely for the humans fish will be fine with whatever natural light they get. If you want you can create a nicer looking tank by planting it up its often better that way make the tank something other than just an empty box of water with a few fish in its also fun to see the fish swimming in and out of the plants as they do in the wild.

      1. Thanks for replying. I won’t bother with the light then. Yes, have plants and coral and some glass beads that they seem to like. Looking forward to taking care of them and learning more about them. Your site here has a lot of information and i really appreciate you taking the time to share your knowledge.
        Cheers, John.

    1. Lighting is to suit the viewer ie: you not the fish the fish will be fine with whatever even just natural daylight coming in through the windows.

      Filtration for a neon only tank can be pretty much anything from just a plain air driven uplift sponge filter to an internal filter to a canister. They’re not massive waste producers so don’t need massive amounts of filtration. Though bear in mind that it is dependent on the stocking of the tank. If you have a 30 liter tank and stick 60 neons in then you’ll need a massive filtration system as you’ve got a massive bio load per volume of water. If you have a 1000L tank and only 10 neons while not recommended you could get away without a filter at all and just water change it once a month as you’ve got a minimal bio load (in this case probably not even enough to feed the nitrogen cycle of a tank).
      I have to say filtration is a common sense approach use what you feel is suitable if you bought a tank kit with filter in it then whatever it came with will be fine as long as you don’t overstock and that is the key never overfill a tank.

      1. because they come from a dense, “jungle like” habitat they prefer low light, lots of shade

        1. yeah darker tanks especially blackwater tanks suit neons well and their colours really shine in blackwater tanks + you need it to be blackwater for them to breed

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