I need help and advice about my new neon tetra tank!

[Kirsten2001]

Hello all! Im new to this website so I hope I’m using it correctly ! This is going to be along post, but please take time to read it if you are experienced as I really need help.

So I need some help and some advice about my new tank. I’ve been wanting to get into the hobby for a long time and I’ve really recently found the motivation to do it. I bought a 40L (10 gallon) tank with a hang on back filter and heater provided, set it up with some live plants and some driftwood and almond leaves, added all necessary conditioners and bacteria, and let the tank run for two days. (Tank was set up last Friday, it is now Wednesday for reference) I am a complete beginner, and am so willing to learn and do right by these animals and plants.

My local fish shop has glowing reviews, with friendly staff who seem knowledgeable and attentive to beginners to the hobby like myself. I had done some research into what kind of fish I would like to introduce to the tank and what their needs are, and my own research as well as advice from the staff in the shop led me to purchase 6 neon tetras last Sunday. I was led to believe that they are good beginner fish, and was not discouraged in any way from buying them. Just yesterday I returned to buy 2 corydoras.

Only a few days have passed, and one of them died last night. It was struggling to swim and was whirling around unable to keep itself straight, and as I panicked and tried to get it into a glass bowl to asses it, it died. I was extremely upset. This then led me to dive into some more extensive research about the breed, and I’m really upset to learn that generally these fish are not at all good fish for beginners, especially not with such newly set up tanks. They don’t have the best immune system and are fickle when it comes to changes in the parameters of the water, I was told 6 is a minimum for schooling fish but more than 6 is better, now I’m down to five. Even the filter I have (which hangs inside the tank) I’ve now learned isn’t the best for providing the water conditions these guys need.

I feel horrible and guilty that I bought them before knowing all this, it is my responsibility to set them up in the correct home, and I think I’ve failed them. I wasn’t discouraged from buying them at all and I feel really let down that the staff in the fish shop didn’t persuade me to wait, or even try and convince me to start with a hardier fish.

Now one of them has died, and I’m noticing some small changes in the rest of the school that are really concerning me. One of the bigger neons has a small lump right under the belly, hard to see but definitely there. I’m not sure if I’m just tricking myself, but I’m even convinced there’s some colour loss in some of their red areas as well. It seems like every time I look at them I’m seeing something to be concerned about. If this is neon tetra disease, I know there’s nothing I can do to save them, and I’m so heartbroken. The response I got from the shop today when I went to get my water tested and explain that one of them had died was so casual and pretty much just “yeah it happens. You’ll probably loose more of them before the tank is mature.” My ethics aren’t that some fish should have to die before I have a mature tank. I don’t think that’s fair on them at all. I just want to know what I should do. Should I take them back? Just leave them be and monitor to see if there are improvements? I don’t want to have to euthanise any fish until completely necessary, but I’m also not going to allow the corydoras to die.

Please help!

I’m case anyone asks, my water was tested today, here’s the results:

Ammonia: 0
Nitrite: 0.25
Nitrate: 0
PH: 7.6

It’s hard to get photos, but I’ve attached one that shows the fish I’m most concerned about, you can see in the reflection that there is a clear bump on his belly.

 

[Obsessed with fish]

I am sorry to break it to you, but the reason for those deaths is because your tank is not cycled. Cycling an aquarium takes around 4-8 weeks, and fish can not be in your aquarium during this 4-8 weeks. I do not know much about cycling, but @Fishmanic has a link to a good article that explains it, and is it fine if you show closer photos of the neon tetra?

 

[Naughts]

Your fish and filter choice are fine so don't be hard on yourself. The problem is not cycling the tank and fish that are unhealthy due to mass production, probably a combination of both things.
Fish stores don't advertise these issues as they prioritise sales over welfare.
Your last water test shows some nitrite so do a large (50-75%) water change. Make sure the new water is dechlorinated and has the same temperature as the tank water.

 

[Kirsten2001]

Thanks for responding, I’ll definitely check that link out . I’m really frustrated with myself for not properly understanding a lot of important information like this, and im super sad that it was made out to me that 48 hours was a long enough period for the tank to run before adding fish. That being said, there ARE fish in there now, so I want to do what’s right by them now instead of beating myself up about what I haven’t done. The neons have been in there since Sunday, and the corys were just put in yesterday. Should I let it be or should they be returned to the shop? Thanks again cxx

 

[Naughts]

Keep them. We can talk you through a "fish in" cycle and moving them again would cause more stress.
Besides, they are with someone who cares now, which gives them a decent chance.
Do the water change, feed very sparingly and refrain from buying more fish for the next few weeks.

 

[Kirsten2001]

Your fish and filter choice are fine so don't be hard on yourself. The problem is not cycling the tank and fish that are unhealthy due to mass production, probably a combination of both things.
Fish stores don't advertise these issues as they prioritise sales over welfare.
Your last water test shows some nitrite so do a large (50-75%) water change. Make sure the new water is dechlorinated and has the same temperature as the tank water.

Thanks for responding! It’s horribly disheartening as a newbie to feel caught between what the so called “experts” are telling you at the fish shop and what a community online are telling you. I know that a lot of fish are bred in such massive numbers that there isn’t a lot of quality control done on them and they have weak immunities

I was wondering if I should do a water change !! A lot of info online says that a new tank shouldn’t have any water changes for at least two weeks, but if it’s best to do that then I certainly will. Thanks again. X

 

[Blackghostknifekid]

Thanks for responding, I’ll definitely check that link out . I’m really frustrated with myself for not properly understanding a lot of important information like this, and im super sad that it was made out to me that 48 hours was a long enough period for the tank to run before adding fish. That being said, there ARE fish in there now, so I want to do what’s right by them now instead of beating myself up about what I haven’t done. The neons have been in there since Sunday, and the corys were just put in yesterday. Should I let it be or should they be returned to the shop? Thanks again cxx

if you have another tank put them in that (if the tank is cycled and has fish that will not eat them)

 

[Naughts]

Perhaps the information saying don't do a water change pertains to fishless cycling.
Both ammonia and nitrite are toxic so test the water daily and do a water change any day that either reading is above zero. This will need to be done for several weeks but hopefully the fish can survive due to your hard work now.

 

[Kirsten2001]

if you have another tank put them in that (if the tank is cycled and has fish that will not eat them)

I don’t have another tank sadly part of the reason I’m so stressed out is that this is my very first time (since I was a child) setting up a tank.

 

[Kirsten2001]

Perhaps the information saying don't do a water change pertains to fishless cycling.
Both ammonia and nitrite are toxic so test the water daily and do a water change any day that either reading is above zero. This will need to be done for several weeks but hopefully the fish can survive due to your hard work now.

You’re probably right! Annoyingly the test I bought doesn’t search for ammonia, just nitrate, nitrite, PH etc etc etc. I’m going to get my hands on a master test kit asap, but to be on the safe side I’ll do a large water change. Thank you )

 

[Obsessed with fish]

Thanks for responding, I’ll definitely check that link out . I’m really frustrated with myself for not properly understanding a lot of important information like this, and im super sad that it was made out to me that 48 hours was a long enough period for the tank to run before adding fish. That being said, there ARE fish in there now, so I want to do what’s right by them now instead of beating myself up about what I haven’t done. The neons have been in there since Sunday, and the corys were just put in yesterday. Should I let it be or should they be returned to the shop? Thanks again cxx

Its fine don't worry, I made the same mistake with my aquarium, and its not your fault its the pet stores fault

 

[Ram419]

Typically you would want to buy cheaper fish if you are going to do a fish in cycle so the neon tetra aren't a terrible price. But I think guppies are more hardier then neon tetra and would be able to deal with the fish in cycle better. I always suggest a fishless cycle which requires you dose the tank with an ammonia source.

You can read about the fish in cycle and the fishless cycles here on this forum here --> https://www.fishforums.net/threads/cycle-your-tank-a-complete-guide-for-beginners.475055/

Oh, also, what kind of substrate are you using? Corys usually need sand.

 

[Lcc86]

I'm not as knowledgeable as others here but the only thing I would add is that cories nees to be in large groups, preferably a minimum of 6 but more is better. That may lead to an overstocking problem given the size of your tank so may be worth seeing if you can return the cories.

 

[Essjay]

Annoyingly the test I bought doesn’t search for ammonia, just nitrate, nitrite, PH etc etc etc.

That sounds as though you have strip testers which don't include ammonia. You can buy separate ammonia testers, most of us use API liquid testers. Those can be bought separately or in a 'master' set containing ammonia, nitrite, nitrate and pH.

Don't beat yourself up, poor advice from a fish shop is common. You'd think they should be the best people to advise but so many of them either don't know or don't care.

 

[sharkweek178]

Thanks for responding! It’s horribly disheartening as a newbie to feel caught between what the so called “experts” are telling you at the fish shop and what a community online are telling you. I know that a lot of fish are bred in such massive numbers that there isn’t a lot of quality control done on them and they have weak immunities

I was wondering if I should do a water change !! A lot of info online says that a new tank shouldn’t have any water changes for at least two weeks, but if it’s best to do that then I certainly will. Thanks again. X

The beneficial bacteria that you're trying to develope live on surfaces, particularly filter media, not in the water itself. Water changes won't hurt your cycle and will help your fish.