I have three goldfish and one died from not eating?

Mostly likely, the fish was ill before you brought it home. If you still have it and the receipt return both to the store for an exchange or refund. Most pet stores will do this within the first 5-7 days of purchase. Also, what types of water treatments are you using?

That's what happens when you're anorexic.

But, seriously, either the fish could've been suffering from a disease, or the change in its environment changed its appetite.

RIP Puck :(

hard to give you a good answer without more information,

was he in a tank or a bowl?

whats your water quality like?

How long was the tank set up before you put fish in there?

try utilising intense protein foodstuff to spice up your goldfish's immune equipment. additionally you are able to try dissimilar drugs, there is one I actual have used myself, that's termed GOLD - FISH risk-free' it enables your goldfish to regain moisture of their physique and regain their urge for foodstuff. It additionally stops them from getting ailments. goodluck(: you're able to shop your tank immaculate to end bacteria moving into your fishes physique.