Adding neons to an established aquarium

BCook0726

Hey guys, I’m new to the forum! My 75 gallon aquarium has been up and running for about a month and a half now. Currently I have 8 glo-fish tetras, 2 mollies, 2 balloon mollies, and 4 guppies. I want to add neon tetras, but I’m torn on how to add them. I’ve read multiple care guides that say you should only add 3 fish at a time, but neons are happy in schools. How should I go about adding the neons so that I don’t overload the tank, but also don’t stress the neons by not adding a school? How many can I safely add at once?
 

Roman96

You could add them at once since it's such a big tank, but they are very fragile. Imo I would do black neons or even cardinals.
 
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jdhef

Welcome to FishLore!

I assume your tank is fully cycled at this point. If so, I would think that adding 6 neon tetra's would be fine. You have a lot of water and the neons have a small bioload.
 
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Dennis57

Hi, and Welcome to Fishlore. Is your tank cycled? When did you add the fish you have now?

Neon's in my opinion are one of the hardest to keep alive, but once you have had them in the tank a few weeks your good to go.

Make sure the water parameters are kept the same because once that changes neon's will stress out and die easily.

If your tank is cycled I would add like 6-8
 
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Leeman75

You could add them at once since it's such a big tank, but they are very fragile. Imo I would do black neons or even cardinals.

Totally agree. In fact, check my recent thread about what I went through with mine just this last week: Why are my Neon Tetras slowing dying? | Neon Tetra Forum | 484404

I know that my one situation doesn't mean that it won't work for you, however, as I found out when I was researching and trying to find out what was going on in my tank, my experience is quite common as Neons are super fragile and seem to be very hit or miss.

Cardinals give you the same colors just laid out differently and are a little bigger, which size is not too much of a concern in a 75, but more importantly seems to not have the same health issues that Neons have.

Edit: And totally forgot to add: Welcome to the forum!!
 
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Roman96

Totally agree. In fact, check my recent thread about what I went through with mine just this last week: Why are my Neon Tetras slowing dying? | Neon Tetra Forum | 484404

I know that my one situation doesn't mean that it won't work for you, however, as I found out when I was researching and trying to find out what was going on in my tank, my experience is quite common as Neons are super fragile and seem to be very hit or miss.

Cardinals give you the same colors just laid out differently and are a little bigger, which size is not too much of a concern in a 75.
Yeah I was actually just reading that thread. I've had similar experiences with neons and although their pretty, they are weak now.
 
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BCook0726

Ive considered cardinals and after reading your replies, that will probably be the way I go. I started with the 8 glo tetras around Dec 4th, then added the guppies a couple weeks later, then the mollies this past Friday. Trying to not overdo it, but can’t wait to have a full thriving tank. I had aquariums years ago, but just recently got back in to the hobby, so I feel like a beginner again and don’t want to kill anything. Thanks for you advice! I’ll probably go with the cardinals just for their hardiness.
 
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veggieshark

I strongly recommend to use quarantine before adding neons to your established tank. Depending on where you buy them, they often are fragile and bring a disease with them.
 
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BCook0726

Seems like neons were hardier when I was a kid and my mom kept them. Maybe it was just bc I wasn’t in charge of caring for them! Definitely going to research cardinals more and probably go with those. I just love to watch fish school together and would do an entire tank of neons or cardinals if I could. My BF wants a variety though so that’s what I went with. I added the mollies Friday, is 2 weeks long enough to wait to add 6 cardinals?
 
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Dennis57

Seems like neons were hardier when I was a kid and my mom kept them. Maybe it was just bc I wasn’t in charge of caring for them! Definitely going to research cardinals more and probably go with those. I just love to watch fish school together and would do an entire tank of neons or cardinals if I could. My BF wants a variety though so that’s what I went with. I added the mollies Friday, is 2 weeks long enough to wait to add 6 cardinals?
Yes they were years ago. Yes you can go ahead and add 6 without a problem
 
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Roman96

Seems like neons were hardier when I was a kid and my mom kept them. Maybe it was just bc I wasn’t in charge of caring for them! Definitely going to research cardinals more and probably go with those. I just love to watch fish school together and would do an entire tank of neons or cardinals if I could. My BF wants a variety though so that’s what I went with. I added the mollies Friday, is 2 weeks long enough to wait to add 6 cardinals?
Is your tank cycled? If so then it should be good.
 
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RelaxingBettas

Hey guys, I’m new to the forum! My 75 gallon aquarium has been up and running for about a month and a half now. Currently I have 8 glo-fish tetras, 2 mollies, 2 balloon mollies, and 4 guppies. I want to add neon tetras, but I’m torn on how to add them. I’ve read multiple care guides that say you should only add 3 fish at a time, but neons are happy in schools. How should I go about adding the neons so that I don’t overload the tank, but also don’t stress the neons by not adding a school? How many can I safely add at once?
I had two, then five, because too small tank syndrome, but with a 29 gallon running now I bumped it up to nine, with three black neons which tag along, they didn't grieve to death by adding to the herd gradually, anyway, that's my experience.
 
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Noroomforshoe

Seems like neons were hardier when I was a kid and my mom kept them. Maybe it was just bc I wasn’t in charge of caring for them! Definitely going to research cardinals more and probably go with those. I just love to watch fish school together and would do an entire tank of neons or cardinals if I could. My BF wants a variety though so that’s what I went with. I added the mollies Friday, is 2 weeks long enough to wait to add 6 cardinals?
Did you cycle the tank before adding the fish that you have? Even if you did, It would not be a bad idea to wait another month to add more fish. Cardinals are still sensitive fish. "often wild-caught, and stunned with cyanide to make them easy to catch" And a 6 week old tank may still be having changes in water quality.
 
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BCook0726

I had it set up for 2 weeks and added the seachem products to stabilize it and add bacteria before adding the first set of fish. I totally get the too small tank syndrome. I was going for a 150 gallon, but the sales associate told my BF that if they aren’t custom built anything over 100 gallons tends to leak in a couple years. We just bought a new place so he said “Nope, nothing over 75 gallons.” I seriously want a bigger aquarium, but I’m glad I’m getting the experience with the 75 first. He told me I could have two 75 gallons, I just feel that a 150 is better suited for the larger fish that I want. Tiger Oscars, Severum Cichlids and that sort. One can dream, right?
 
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Cherryshrimp420

Hmm I've had a lot of success with neons and found them to be quite hardy fish. Maybe I should make a post about how I kept them?
 
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Dennis57

Hmm I've had a lot of success with neons and found them to be quite hardy fish. Maybe I should make a post about how I kept them?
I've had neon's for 43 years of fish keeping. Now I have 25 in a 125 community tank, 12 in a 55, and 6 each in each 20 that i have.
 
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Fisch

Welcome to fishlore....There should be another question regarding your water parameters. While Guppies like higher pH and water hardness, Neons not so much.

Just a word of caution. Please, please, please read up on quarantine. I went through the heartache and panic with Ich introduced by seemingly healthy Neons. It wiped out half my Neon population before I could get a handle on it, not to mention the stress I put onto my healthy fish population. My second batch went through ich in the quarantine tank, it was much easier to handle.
I also thought it could not happen to me, I was impatient. Now I do not introduce any new fish without quarantine.
 
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andy305mia

Im a little late....I have neons and they aren't that delicate so long as you acclimate them right and the more you add the better. In your 75 you can do 20-30 neons easily assuming you have decent filtration. Neons are nervous so the more you add the safer they feel. Drip acclimating would be your best bet. I've had neons for 10 years or so best chance is going to be in a well established tank which is not the same as cycled. Oh yeah and plants plants and more plants. Give them hiding spots. Don't be discouraged, I have kept many fish and Neons I will ALWAYS keep, they are the most popular fresh water fish for a reason. I currently have 20 in my 40 breeder some are 4 years old, haven't lost one, been in different tanks in my house. All my tanks are very well established tho
Ive considered cardinals and after reading your replies, that will probably be the way I go. I started with the 8 glo tetras around Dec 4th, then added the guppies a couple weeks later, then the mollies this past Friday. Trying to not overdo it, but can’t wait to have a full thriving tank. I had aquariums years ago, but just recently got back in to the hobby, so I feel like a beginner again and don’t want to kill anything. Thanks for you advice! I’ll probably go with the cardinals just for their hardiness.
Cardinals would probably be a better fit temperature wise, and you have the space for them as well. I don't keep them because they cost twice as much as neons and they are wild caught. I have had much better luck with neons and they are cheaper. Neons are supposed to be in cooler waters, mine have been doing well in 79 degrees. They probably won't live as long but I had to find a sweet spot since I have them mixed in with German Rams
 
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Cherryshrimp420

Im a little late....I have neons and they aren't that delicate so long as you acclimate them right and the more you add the better. In your 75 you can do 20-30 neons easily assuming you have decent filtration. Neons are nervous so the more you add the safer they feel. Drip acclimating would be your best bet. I've had neons for 10 years or so best chance is going to be in a well established tank which is not the same as cycled. Oh yeah and plants plants and more plants. Give them hiding spots. Don't be discouraged, I have kept many fish and Neons I will ALWAYS keep, they are the most popular fresh water fish for a reason. I currently have 20 in my 40 breeder some are 4 years old, haven't lost one, been in different tanks in my house. All my tanks are very well established tho

Cardinals would probably be a better fit temperature wise, and you have the space for them as well. I don't keep them because they cost twice as much as neons and they are wild caught. I have had much better luck with neons and they are cheaper. Neons are supposed to be in cooler waters, mine have been doing well in 79 degrees. They probably won't live as long but I had to find a sweet spot since I have them mixed in with German Rams

Yeah I feel like since Neons are not the superhumans of the fish world like guppies, people are having trouble and expecting too much from them...

They are fairly normal fish, but they definitely require a proper planted tank with good maintenance. They will certainly not survive in those 10gal starter kits with fake plants and colored gravel. The other thing I noticed is they like darkness. A heavily planted shaded tank where the neons are not hit by direct light will do wonders.
 
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Roman96

Yeah I feel like since Neons are not the superhumans of the fish world like guppies, people are having trouble and expecting too much from them...

They are fairly normal fish, but they definitely require a proper planted tank with good maintenance. They will certainly not survive in those 10gal starter kits with fake plants and colored gravel. The other thing I noticed is they like darkness. A heavily planted shaded tank where the neons are not hit by direct light will do wonders.
Guppies aren't hardy either, at least not fancy strains. I'm saying you've just been lucky. Have you dealt with the neon specific columnaris strain? Mine lived for a good 4 months until I introduced it, so they are hardy in that sense, but the columnaris Is so common its just not worth. If you can source good stock, then go for it, but if you have to buy your fish from a LFS or petco then don't.
 
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jake37

Cardinals also prefer warmer water than neon. The other concern you might have when adding new fishes to an established tank are diseases. The fishes you have are fairly hearty and disease do occur when adding new fishes they are not a given.
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Adding 3 or 6 or 9 neon at the same time is the same if they are all purchased from the same source (store). However long term you might look into a quarantine tank or check if your shop quarantine fishes before selling them. Some do but most don't.
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fyi - everyone say neon are more fragile than cardinal but the ones i purchased 2 months ago are doing just fine - i also have a lot of cardinals in another tank and my track record from the local lfs has been mixed - the ones i've purchased via mail-order have been a+.

Cardinals give you the same colors just laid out differently and are a little bigger, which size is not too much of a concern in a 75, but more importantly seems to not have the same health issues that Neons have.

Edit: And totally forgot to add: Welcome to the forum!!
 
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Cherryshrimp420

Guppies aren't hardy either, at least not fancy strains. I'm saying you've just been lucky. Have you dealt with the neon specific columnaris strain? Mine lived for a good 4 months until I introduced it, so they are hardy in that sense, but the columnaris Is so common its just not worth. If you can source good stock, then go for it, but if you have to buy your fish from a LFS or petco then don't.

Do you mean the Neon Tetra Disease? Yes I've had it when I was an absolute beginner in fishkeeping and didn't know about cycling and all that.

I had success with them much later when I had a 75gal devoted to them. Again, not many people keep them in tanks this big and it only gets harder the smaller the tank you have.

Their weakness is definitely related to water quality and overfeeding. In a tank with Neons and Zebra Danios, Neons will display symptoms first but really it's just poor water quality affecting all the fish. A lot of times the Neons will die out first, at which point the tank bioload have decreased significantly and thus the remaining fish manage to survive. This ends up giving the impression that Neons are "weak".

There is also a second factor which I don't see addressed nearly enough. The Neons you buy from LFS are actually JUVENILES. They are babies, and NOT adults. You'll see labels like "sm" or "lg" for small and large Neons but they are BOTH still babies. Adult Neons are actually quite big, about the size of the "Cardinals" you see in LFS. If a Neon actually gets to the adult stage they are quite hardy and mine have survive through many poor maintenance schedules and all sorts of laziness on my part.
 
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Roman96

Do you mean the Neon Tetra Disease? Yes I've had it when I was an absolute beginner in fishkeeping and didn't know about cycling and all that.

I had success with them much later when I had a 75gal devoted to them. Again, not many people keep them in tanks this big and it only gets harder the smaller the tank you have.

Their weakness is definitely related to water quality and overfeeding. In a tank with Neons and Zebra Danios, Neons will display symptoms first but really it's just poor water quality affecting all the fish. A lot of times the Neons will die out first, at which point the tank bioload have decreased significantly and thus the remaining fish manage to survive. This ends up giving the impression that Neons are "weak".

There is also a second factor which I don't see addressed nearly enough. The Neons you buy from LFS are actually JUVENILES. They are babies, and NOT adults. You'll see labels like "sm" or "lg" for small and large Neons but they are BOTH still babies. Adult Neons are actually quite big, about the size of the "Cardinals" you see in LFS. If a Neon actually gets to the adult stage they are quite hardy and mine have survive through many poor maintenance schedules and all sorts of laziness on my part.
No, I'm talking about the non-specific columnaris strain. NTD is also bad though.

I agree that if you can source non-inbred neons then they are hardy, but that's hard nowadays. Same with guppies and other common fish in the aquarium trade.
 
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jake37

Bit surprise your local cardinals are wild caught as florida has some of the largest collections of tank bred cardinals.

Cardinals would probably be a better fit temperature wise, and you have the space for them as well. I don't keep them because they cost twice as much as neons and they are wild caught. I have had much better luck with neons and they are cheaper. Neons are supposed to be in cooler waters, mine have been doing well in 79 degrees. They probably won't live as long but I had to find a sweet spot since I have them mixed in with German Rams
 
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Cherryshrimp420

No, I'm talking about the non-specific columnaris strain. NTD is also bad though.

I agree that if you can source non-inbred neons then they are hardy, but that's hard nowadays. Same with guppies and other common fish in the aquarium trade.

I never had any issues with columnaris or any fish disease. Just low feeding and water changes solved my issues. ALL fish will show some signs of bacterial colonization when they are near death/dead. That's bacteria starting to feed on weak fish and starting the natural decomposition process early. It really doesn't matter which strain of bacteria takes over (ie. Columnaris) and there's really no point treating for that specific bacteria. Instead, we should be focusing on what caused the fish to become weak in the first place. Usually it is just too much waste in the water.

The Neons I bought came from my LFS but that was 10+ years ago. I do wonder though, over these years it might be possible that Neon became significantly inbred.

The most recent fish I bought were harlequin rasboras and dalmatian mollies (from LFS). I didn't notice any inbreeding in them and they're living just fine in my tanks...
 
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Roman96

I never had any issues with columnaris or any fish disease. Just low feeding and water changes solved my issues. ALL fish will show some signs of bacterial colonization when they are near death/dead. That's bacteria starting to feed on weak fish and starting the natural decomposition process early. It really doesn't matter which strain of bacteria takes over (ie. Columnaris) and there's really no point treating for that specific bacteria. Instead, we should be focusing on what caused the fish to become weak in the first place. Usually it is just too much waste in the water.

The Neons I bought came from my LFS but that was 10+ years ago. I do wonder though, over these years it might be possible that Neon became significantly inbred.

The most recent fish I bought were harlequin rasboras and dalmatian mollies (from LFS). I didn't notice any inbreeding in them and they're living just fine in my tanks...
Like I said, your lucky to have good sources near you. Just type neon tetra or guppy and look at all the problems people have on here. The neon specific columnaris affect even healthy fish, all it takes to spread is contact to contact. Keeping good water quality is important for prevention, but it's not a 100% sure method to prevent disease.
 
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APColorado

For my 125 g tank, I've added 30 neons to the tank after being quarantined and never had an issue.
 
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Cherryshrimp420

Like I said, your lucky to have good sources near you. Just type neon tetra or guppy and look at all the problems people have on here. The neon specific columnaris affect even healthy fish, all it takes to spread is contact to contact. Keeping good water quality is important for prevention, but it's not a 100% sure method to prevent disease.

I do see a lot of Neon Tetra problems on here, Fishlore seems to be filled with them. Maybe there is some deadly Neon disease floating around?? But I don't see many well maintained planted tanks and it's really hard to pinpoint the issue in small overstocked tanks.
 
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Roman96

I do see a lot of Neon Tetra problems on here, Fishlore seems to be filled with them. Maybe there is some deadly Neon disease floating around?? But I don't see many well maintained planted tanks and it's really hard to pinpoint the issue in small overstocked tanks.
True, I agree that's also a factor.
 
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jake37

Just remember it can be difficult to filter the noise from credible information. After all a lot of first time fish owners buy neon and - well - don't take the best care of them...
 
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Leeman75

It's also important to keep in mind that many have varied experiences with fish. Obviously, on here you have several people who have kept Neons for years and have had no problems. Wonderful for them! Others, including myself recently, have experienced loss of fish despite being on top of large regular water changes, planted tank, excellent filtration.

Choose your own path and I hope that it works in a fantastic way. At the end of the day, we're all trying to help by relaying our own experiences.
 
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