Mopey Fish?

Question

I came into work today and my fish don't seem as active as they usually are. I changed the water on Friday and they were fed over the weekend. They ate when I fed them this morning, but they still just kinda lightly swin on the bottom 1/4 of their 2.5 gallon tank. Any ideas what's wrong and how I can perk them up?

They are goldfish. They've been in this tank for over 7 months now without a problem./ I was always told rule of thumb, 1 inch of fish per 1 gallon of water. I have 2 fish in 2.5 gallons.

I forgot to add that I always use a water conditioner along with an algae treatment. Never had problems with that either.

There is a filter in the tank. It is a gravel filter with a air stone. I replace 1/2 the water each Friday and clean the gravel with one of them clear vaccuum tubes.

Answer 1

You didn't specify what kind of fish they were. The fact that your tank is 2.5 gallons is probably the culprit. You can get away with keeping a betta in a tank that size, but not much else. Even the small tetras need more room because they are active swimmers and schoolers, so although they may seem okay for a while in a 2.5, they will eventually succomb to the lack of space.

Otherwise, do you have a heater? If your building turns off the heat over the weekend, it might get too cold in the building.

Edit: Yeah, the problem is that they are goldfish in a 2.5 gallon tank. The 1 inch per gallon rule is bogus. It can sort of apply to small bodied fish like neon tetras, but not to goldfish. First of all, goldfish are not 1" fish - even the small, fancy-type goldfish grow to 7-8" long. Other types like commons and comets grow to 18-24". Fancy goldfish need 15-20 gallons of water per fish, and if properly cared for, can live 10-20+ years. However, if kept in tanks too small, they will not live long and will eventually succomb to stunting and ammonia poisoning. It is good that you're doing weekly water changes - I know it's tought to do everything right because there is sooo much misinformation out there, and petstores are usually full of BS. Look into getting a used fish tank. You could get a used 30 gallon or 20 gallon "long" with filter, hood and lights, for probably 30-40$. If you can only have your 2.5 gallon, please bring the goldfish back to the petstore and get a heater and a betta fish.

Answer 2

What kind of fish are they? What is the water temp? What are the water params? How many fish are there? Is there a filter on the tank?

Without knowing those things it would just be a guess at what is wrong with your fish.

You are killing those goldfish, they need a minimum of 10 gallons each when babies and 20+ when adults. The 1 gallon per inch rule of thumb applies to slim bodied fish like tetras and it's for their adult size not the size when you buy them. Goldfish can reach 8-12 inches and live for 20+ years if properly cared for.
Your water params are probably very bad and it is poisoning your fish, 1/2 a gallon once a week is not enough even if you kept a correct type of fish, like a betta in there. The only chance they have at surviving is if you buy them a new tank and get them a good filter. Please do some research on the proper way of taking care of a goldfish, it isn't as easy as some people think. Check this site out for starters, http://kokosgoldfish.com/

Answer 3

2.5 gallons is much too small for 2 gold fish. Goldfish poop a lot and foul up the water. You probably want to do a water change every 2-3 days. I suggest you buy a water testing kit since water conditions can change during the week.

Answer 4

my fish did exactly what you have described although it was only one fish and it ended up committing suicide by jumping out of its tank ... no idea why or how tho i hope Ur fish are OK

Answer 5

if the water temp cools down they are not as active, they are cold blooded

Answer 6

My little fishy, Equinox, he is doing the same. He's a beta fish and if you find answers about your fish then please share with me.