Fish swimming at top of the tank

[JEK]

I have 3 neons and a small tetra (not sure what species) in a 5 gallon tank. I have had the tank up and running for over a year with no issues. Saturday (3 days ago) I did a 40% PWC and changed one of the filters out (there are 2 and it says to change one every 2 weeks. I rinsed it well first) and this morning all of the fish were at the top gasping for air, and havent stopped. Even the tetra that is normally very shy is up at the top. I conditioned the water before adding and checked temp like I always do. The tank was pretty dirty at the bottom in the rocks so that is why I did so much of a water change. Not algae but food particles and poo I guess. I have checked ammonia, nitrite, nitrate (all 0), and pH, GH, and KH and everything is perfect! Any ideas what the issue may be? I don't want to loose any of the poor guys. If it makes any difference my other tank, a 55 gallon with one 8" Oscar, was also cloudy this morning and I cleaned his tank the same day. He isn't acting funny though.

 

[JEK]

Well, in the last 30 minutes one of my neons has died. . Please help before I loose any more!

 

[Brookster123]

You said you changed the filter? How often do you change it? What is your maintainance schedule? Wc?

 

[venymae]

Having a lot of detritus (poo, food, etc.) stirred up and also replacing one filter pad (so lets say 1/2 of your bacteria) would make me guess that you are going through a mini-cycle. I would gander that your ammonia and nitrite levels are probably pretty high. It would not hurt to quickly do a water change, then test. Filter pads really don't need to be replaced until they are falling apart and should only be gently rinsed in old tank water when needed.

 

[venymae]

+1 to brooksters questions about what your maintenance schedule is like on this tank

 

[JEK]

I do a PWC about once every month, and change one filter out then. I just did another PWC after I pulled the dead neon out. I did check the ammonia and nitrite and both are zero.

 

[Brookster123]

I don't know man.. Maybe they are getting nitrate shock?? A dirty tank and filter will jack the trates up, than suddenly providing a clean clean tank could mess with them? Weekly wc and the least amount if filter play are recommended here usually..

 

[JEK]

Thanks. I guess maybe that is it. I will try and start doing more regular water changes and less filters and see if that helps. Hopefully I don't loose all these guys .

 

[absolutangel04]

First off, I am quiet sorry about losing a fish. I know that stinks, especially after you have had them for awhile.
So, one possible issue is that your pwc schedule is pretty low. The filters will allow bacteria to populate that convert the ammonia in the fish poop, but changing the filter pad then takes away all of those bacteria and leaves your fish to swim in the ammonia. These bacteria also populate the substrate, tank walls, and on any decor you have, so that helps. I definitely suggest not changing out the filter pads though. It will save you some money and be better for the fish. Now, that aside, it is possible the fish didn't adjust well to that big of a pwc because of the state of the water parameters before the change. It is possible that the parameters had degraded a a fair bit and the new water "shocked" them, like Brookster said.
Another issue I can see if that 5g is rather small for neons. I know you have said it has worked for a year, but keep in mind these are fish that should be living plenty longer than a year. Fish kept long term in small spaces can get a bit fragile, and don't tend to live out their full life spans and are commonly not that hardy. If you are able to, I would consider upgrading to a 10g or so to give them a bit more space. I don't mean to be harsh, just offering some advice based on my experience.
What kind of test kit are you using? You might want to consider testing in between your scheduled pwc to see what the parameters are like so you can catch it in the future before it gets too bad. The filter doesn't remove nitrates, and their build-up can cause long term issues.
Good luck! And I hope you don't lose more fish.

 

[JEK]

Just so I know and don't cause any problems like this in the future, how often should I be doing PWC? Filter changes? My big tank with my Oscar I have never really had an issue with but I mostly just rinse his filter parts off and only change one aspect of the Fluval filter every few months. Usually I just rinse the pad out and then change the charcoal every 3-4 months or so, but never the C nodes or pad on top of that. This small tank is confusing as the filter is built in and has 2 filter pads. They say one every 2 weeks but that does seem like a lot. Worst case scenario and I loose all these guys, any reccs on a good small fish or 2 for it? They have to be strong swimmers bc unfortunately the filter in there is pretty strong. I tried betas but they usually don't last more than 6 months as the filter blows too strong and stresses them. I can't turn it down though, and if I unplug it then the light doesn't work either :-/. Cute tank, horrible design....

 

[absolutangel04]

Just so I know and don't cause any problems like this in the future, how often should I be doing PWC? Filter changes? My big tank with my Oscar I have never really had an issue with but I mostly just rinse his filter parts off and only change one aspect of the Fluval filter every few months. Usually I just rinse the pad out and then change the charcoal every 3-4 months or so, but never the C nodes or pad on top of that. This small tank is confusing as the filter is built in and has 2 filter pads. They say one every 2 weeks but that does seem like a lot. Worst case scenario and I loose all these guys, any reccs on a good small fish or 2 for it? They have to be strong swimmers bc unfortunately the filter in there is pretty strong. I tried betas but they usually don't last more than 6 months as the filter blows too strong and stresses them. I can't turn it down though, and if I unplug it then the light doesn't work either :-/. Cute tank, horrible design....

I know that many filters say that, but it is unnecessary. They say that so they will get more money by selling you more filter pads. Just rinse out the filter pads in used tank water to get the gunk off when it looks like there is too much gunk on it. Honestly, charcoal is not necessary in tanks either and it removes medicines from the water which is inconvenient if you ever need to treat anything. It doesn't hurt though.
For pwc, I suggest doing about 50% weekly. Some people do a little more or less depending on stock, but 50% is a good number to start with. If you test in between pwc, you will have a good idea of what your individual tanks needs too.
If you did have to restock, I would look into ember tetras or chili rasboras. They stay smaller than neons, and are pretty cute. Embers are sometimes seen at a decent lfs, chilis are harder to find. There are other dwarf rasboras that would be good too.
Another option is a female betta. They have shorter fins which makes them more mobile, but you can still find gorgeous colors. I have a 10g with a pretty strong built-in filter and the female bettas do fine in there, even with a decent amount of current.
Another option to look into are red cherry shrimp. They are awesome little guys, and you can usually sell the offspring you get.
In the meantime, hopefully your little guys do ok. Let us know if you have more questions, or need more specific answers.

 

[JEK]

Thanks so much! I have since lost all the neons. I'm heartbroken and feel terrible. . I'm hoping my last tetra will hang in there but he is still sucking air from the top and looking poorly, so I don't have high hopes. I think I will have to clean out the tank and then re-cycle it. But I will definitely look into those! We have a great fish store here in Houston and will go there to check out for those.

 

[anibis]

I'd do another 50% water change.

You hadn't done a pwc in a month, your nitrates should have been high. You did a 40% change, and said your nitrates read 0 after. That just doesn't add up, you didn't do a 100% change, so you should have some readable nitrates.