is feeding off the parents the best idea? if you do wont that only leave you with sibling guppies to breed for more stock?
which will lead to inbreeding and deformities. He should stick with geting rid of the fry by moving guppys who are about to give birth into a seperate tank (5g) and moving them when it's over.
That has been proven to be false! Inbreeding amongst Guppies does no harm! What does cause harm is letting them breed all willy nilly without any "culling"(predation) from you to remove the week and deformed from the gene pool before they are able to breed and pass off the "bad" genes!
Some of the most popular Fancy Guppy strains have been inbred for over 20 years easy!