You really need to test your water then as I'd put money on the fact that
it's this which is causing the problem. Buy a kit or take it to your local
aquatic store and ask them to test it for you. Goldfish need at least 10
gallons each and I guess your tank is no where near large enough for the
quantity of fish you have in it.
Mel.

"ab" wrote in message
...

"Mel" wrote in message
k...
The very first thing to do is to check your water quality. What are your
ammonia, nitrite , nitrate and PH levels?

Haven't a clue. However, I use a recommended product called "aquasafe*
, everytime I change water in the tank &
in the 18 months that we've had the fish/tank we've had no other
*casualties*. It's a 4 foot tank, with 2
pumps (either end ) running.



Also what size tank are the fish in? Should be pretty big if you have 15
goldfish in it!