Recently i noticed 1 of my neon tetras mouth was open and it was just swimming round with it open without closing it at all. Later that day it died and i thought it was to do with it being a new tank set up. I have just seen another neon with exactly the same symptoms plus it did not eat anything when i fed them. Apart from this everything seemed to be running well and all other fish look healthy as ever.

Can anyone help please??

Size: 25g
Occupants: 5 neon tetras, 1 catfish, 1 pink danio and 4 glow light tetras.
Plants: 3 live plants

Thankyou :huh?: :huh?:

size: 25 litres.................sorry, MY BAD!!! :bash:

How new is this tank? Did you cycle it before adding fish? If its an established tank you might just need to do a water change. Thats alot of fish for a 6 gallon tank.

It sounds small but theres alot of space in there to be honest.

I did cycle it yes and im adding 5 at a time week by week, is this ok?

Are you just adding water as topoff or are you actually taking water out in a water change?

Taking water out but not sure how much to take out to be honest, just guessing.

also not long before they die it just started floating around and sinking like it couldnt swim or something. I DONT GET IT!!!! :tdown:

if it's a new tank.. and you cycled the tank.. even with one fish in it..it's not fully cycled ...

one fish will stabalize the tank and then once it's stable, you can add another fish.. if you've cycled and then dumped all the fish in at once .. that most likely upset the "chemical balance" in the tank thus meaning that the nitrates and ammonia spiked due to the over stocking of the tank..

I would maybe consider getting a larger tank, or taking some of your fish back to your LPS/LFS.... 6 gallons should only really comfortably hold an inch or so of fish per gallon... 11 or so fish in a 6 gallon isWAYYYY too many fish.. I know it may look roomey.. but it's definitely over stocked

ok thanks for your help. :thanks:

Do you have a test kit? If not, get one and post your paramaters, Ammonia, Nitrates, Nitrites, Ph.
Until you get a bigger tank I would suggest doing 30% water changes every few days, but I would suggest getting at least a 10 gal but preferably a 20 gal tank soon. The Danio is a very active fish and needs room to swim, Neons are very sensitive to water conditions and paramater fluxuations, and a bigger tank is much easier to stabalize and keep stable.
Good luck!

:goodpost: