When To Move Fry To Grow Out

[tkdjr1186]

So as some of you may know my yellow labs did some breeding and now i have 16 Yellow Lab fry. I'm curious as to what size you guys typically wait for them to get to before you move to grow out tank? I am rehoming the fish in my 20 gallon and using it as my growout tank. Also what should i use to cover the intake of my filter in the 20 gallon so they don't get sucked up.

Attached is a picture for size reference.

 

[Fish Guy]

I usually move them right into my ten gallon right off the start. I cut two slits down through a filter sponge/foam and push the intake tube down into the sponge, I have found that works pretty good.