I Think My Fish Is About To Die!

[xxxpinkladyxxx]

We have four pink widow fish and a couple of months later, we bought two of the fish that clean the tank (they look a little like mini crocodiles). Anyway one of them just disappeared after about two months. We do have cats but I don't see how they could have got hold of it because them fish are very shy and are generally swimming along the bottom. We couldn't find it anywhere and still haven't found it.

Now our other crocodile fish looks like it is about to die. We have had this one for about 6 or 7 months and I just looked at the tank and it was just sitting at the bottom and I thought it was dead. It isn't but I think it is on it's last leggs (or fins should I say). Is there anything I can do? Or could it just be it's dying of old age? My boyfriend tried to lift up the crocodile fish to nearer the surface in case it needed oxygen but it didn't seem to improve and then just floated back down to the bottom. Is there anything I can do to save my little fish?

 

[black angel]

We need to know exactly what type of fish it is to help. Can you get a pic of it?

Also size of tank, any other fish and how long it has been running. Do you test fro ammonia, nitrite, nitrate and ph?
How much water changing and how often?
Do you gravel vac the bottom or is it sand?

 

[xxxpinkladyxxx]

We need to know exactly what type of fish it is to help. Can you get a pic of it?

Also size of tank, any other fish and how long it has been running. Do you test fro ammonia, nitrite, nitrate and ph?
How much water changing and how often?
Do you gravel vac the bottom or is it sand?

The tank is 17.5 inches wide, 11.5 high and 5 deep. We did a 25% water change this morning but, if we are honest, haven't done a water change for some time before that but the pink widows seem fine. Here is a picture of the fish



We are kind of new to this and we haven't vacuumed the bottom which is gravel. We assumed that our little crocodile cleaned this because he cleans all the algy out (brown and green).

 

[black angel]

Its either a siamese algae eater or the chinese algae eater. I suggest doing a google and findng out exactly how to look after it. I know the siamese is really sensitive to bad water and will die if the tank is polluted. Clean the filter using old tank water and squeeze out the sponge rather than replacing it and do 50% water changes each day for a week and see if that helps bring him round.
Also it sounds like the tank is too small and under filtered so you should look to get a 20 gallon tank which will be easier to maintain.