what are we doing wrong

[guichard]

Since November four of my son's five fish have died. what are we doing wrong? we have a small tank with a pump,gravel and plastic plant in it. I change the water about every three weeks and use tap safe in the water. I use Aquarian goldfish flake food and have cut back feeding them from twice to once a day. they are not in full sun light but in a corner of the front room. I clean the sponge of the filter in tank water only yet still over a period of nine months we have lost them and all from different things, swim bladder,white spot,fin rot, untill I suss out where we are going wrong I don't want to replace them. In the clear tube of the pump is red staining that doesn't shift when cleaned , could this be the root of the problem ?

[rumanshu]

when you change the water do you make sure you leave 1/3 of the existing water in the tank? I would try replacing the pump, or if you have a aquarium near by, ask them about the red stain. Unfortunately, if one fish is sick, the bacteria could pass to the others, and they could all get sick. Have you also thought that maybe you bought sick fish in the first place and that you're not actually doing anything wrong?

[morg_monster]

since I was 15 (I'm 23 now) I've had so many goldfish, none ever lasted more than 9 months and most much less, even though I thought I always did everything by the book. Now I've had a pair of fantails which have now lasted for 2 1/2 years, I'm doing nothing different. One thing, you mention that you have a small tank, I don't know the dimensions but with 5 fish you probably are overstocking. A general rule is 1 inch of fish per 24 square inches of surface area. And this is when they are fully grown. Don't give up on them, if you've just got one left it is probably lonely. If I were you I would introduce fish back slowly. Just leave it at two fish for a month, then if everything is ok add another if there's enough room. And don't pick fish in the pet shop if any of the other fish in the tank look sick.

[2nosey]

try this website it will answer, if not all most of your qestions http://www.geocities.com/Tokyo/4468/