Look pretty Altum like to me. To told you this?
In my experience, I was doing 50% changes once a day with fry and it wasn’t enough so will do morning AND evening when I get to that point again. I never had any problem with siphoning fry when they were in with parents, parents always put themselves between hose and fry, you will get attacked by the parents though. When the fry are in their own tank and a bit bigger there’s nothing I could ever do about siphoning fry. If you are going in to a bucket, pull them out and back in the tank. If you are going straight down a plug etc. put a net at the end of it or something to catch them. I would rather that than have a net on the front end and them be trapped against that while water is being pulled through.