gdefc100

I have a brand new -- had it a week --small tank (3 gal.) for my son. It has 8 tetras, 3 plants. It was a kit from Eclipse, bought at PetCo., whose salesman assured us we were not overcrowding (tho' we probably are). All fish except one seem to be doing very well; the water quality (I've tested it a number of times) is good. The one fish, however, appears not so much ill as horribly anxious. It pretty much stays put and hyperventilates. It eats well, and swims fine when it does swim -- which is mostly when its species-mate chases it. Is there anything I can do to help? I hate seeing it suffer. I want to be a responsible owner & do what's right. Thanks!
gdefc100

Lucy

Hi gdefc welcome to Fish Lore

Unfortunately, the salesman gave you bad advise. The general rule of thumb is 1" of adult fish per gallon of water.....depending on the fish. So you are very over stocked.
Your fish are probably suffering from ammonia poisoning. Please read this, it will explain it to you.
http://www.fishlore.com/NitrogenCycle.htm

In the mean time, you should be doing water changes daily.

Not many fish can live in 3g. A betta would love 3g's!
My best suggestion for you is return the tetras, cycle your tank without fish or get a larger aquarium for your tetras. With 8, and assuming they will grow to 1.5" you'd need at least 12 gallons.

Here are some other good things to read:
READ FIRST: Freshwater Beginner Important Topics

I know it's a lot to read, but it will be well worth it.

Good luck.

COBettaCouple

Welcome to Fishlore.

Yea, Deathco strikes again! Are you using strips (notoriously inaccurate) or the API kit?

That many fish would need a 20 gal. tank and they're likely to start injuring each other, starting with that one that would seem to be at the bottom of the pecking order. I'd recommend using Prime to treat the water (1 drop per gallon) and doing daily water changes of 50% until the tank is cycled.. but it will take a larger tank to accomplish that really.

tzqng8

Did this little tank even come with a filter? My assumption is not. That is a very small tank. If not, you need a tank that has one. And you need a little submersible heater.

Depending on what you want to do (keep those fish, take those back and get something that fits, etc.), we can definately help with some suggestions. I'll be happy to do give you some links to some good equipment, but, we'll need to know what you want to do next.

Also, listen to Shawnie and Betta Couple. Smarties all around.