I have an orange and black platy and it keeps just sitting at the bottom of the tank. Is it sick?

Question

I just got it four days ago from petco. I got it because my son did a project at school and brought home a guppy. I wanted the guppy to have company so I went to the pet store and got 3 other fish. I got a Tetra which I took back because it kept nipping everyones tails. All the fish were hiding because they were scared. I got a danios and the tetra nipped its tail the entire first day. The next morning the tail was floating and the danios was dead. I took the dead fish back and returned the "evil" tetra. The people in the pet store told me to wait a few days before I introduced more fish to the tank. Now its just the guppy and the platy. The platy swims well but when I feed them the guppy goes to the top to eat and the platy just waits at the bottom or middle of the tank for the food to fall. I know it can swim to the top because I have watched it swim up there several times. Is this normal behavior for a platy and why does it just sit on the rocks like that 30min at a time?

Answer 1

It's most likely just still stressed from the tetra. I would give it a day or two before assuming anything else might be the problem. The people at Petco were at least on the right track when they told you to wait about adding more fish. Assuming this tank has only been running a few days, you need to wait at least 2 weeks before adding any other fish. It takes that long for the nitrogen cycle to establish itself in a new tank and be safe for many fish at all.

MM

Answer 2

I think your platy must be VERY stressed. Platies live to eat and make babies and if your platy isn't dashing right for that food, it can't be feeling well. Besides that, your fish would be happier if you stuck to groups of the same species. Liverbearers are very social and will be more active and playful in groups. Tetras are schooling fish, which means they actually feel fear-stress when kept alone or in small numbers.

But I agree with MM that you definitely need to stop adding fish for a while because your tank is cycling. While the bacterial colony builds to stabilize the process, the tank is undergoing spikes of chemicals that are created by the fish's waste and any leftover food in the water. Those chemicals, first ammonia and then nitrite are highly toxic and will be causing stress and painful physical damage to the fish. The more fish you add the more quickly the chemicals build and the more fish you'll lose.

Start doing partial (20-30%) water changes every day or every other day to relieve the effects of the toxins on the fish. The only way to know when you can slow down on these is to buy test kits and test the water daily. Whenever you have an ammonia or nitrite reading above zero, you need to change some water. Eventually, you'll be able to get away with weekly water changes when the cycle settles down.

Do a websearch "cycling a tank" or read this link for a full explanation of what you're looking for: (and good luck!)

Answer 3

Eating the food as it falls (middle feeding) is normal for a platy... some fish are "top feeders" or "bottom feeders"... platys are "where ever it suits them at the time" feeders. I'd be more concerned about the sitting on the rocks... sounds like a water quality issue... but with your tank being so young, that's expected.... When you took your fish back, did you take a water sample with you? If you didn't, run one by - Petco does free water testing. (I'm assuming your amonia is high.)
if you're not familiar with the nitrogen cycle- this explains it http://www.petco.com/caresheets/fish/NitrogenCycle.pdf
If you want to help your tank along, there's a product called NutraFin Cycle Biological Aquarium Supplement that helps mature a new tank. (You can go in and just ask for "Cycle"- they should know what you mean) I personally prefer to let nature take it's course... but this stuff's a big seller at our store and I've had nothing but positive feedback from customers about it.

Answer 4

Tetras are schooling fish and must be kept in groups to prevent aggression/fear. Danios are also schooling and can be quite the fin nippers themselves. The platy is probably just stressed, though I suggest you quarentine new fish for a few weeks before adding them to the tank.
You didn't say how big the tank was. Is it big enough to handle the bioload you added?

Answer 5

All these fish need to be in schools of 4 or more to less stressed. The problem is you have such a variety of fish, and possibly a small tank, that you couldn't support the amount needed. 1" of fish needs 1 gallon of water. 12 1.5" fish need 18 gallons of water. A 20 high with 1.5"of gravel, has about 18 gallons in it.