Do I need to water change fry tank with moss?

[caykuu]

The question is pretty much the title! Do I still need to water change a 5 gallon guppy fry tank, since it has a pretty large mass of java moss in there to take in the ammonia/nitrites/nitrates? It's a cycled tank. (also a sponge filter and airstone, just for the record)

A poster on another thread said that guppy fry release a hormone that inhibits growth, hence making water changes necessary... but this is the first I've heard of something like this; is it true?

 

[librarygirl]

I've heard that too actually; I've read of breeders doing 50%-100% water changes from every 12 hours to every 2-3 days because of this, not sure if they do need that much, but the breeder mentioned their fish seemed to grow a lot faster with more frequent water changes. They need to be fed often so that could compromise water quality more easily as well. I don't have experience myself though what I've read confirms what you've heard.

 

[bettaowner]

Well the hormone is only released when the tank is too small. The rule for fry is 2 fry per gallon of water.