Help with substrate debate

My buddy and I have been debating on having pool filter sand as a substrate. He is planning on getting juvie axies tomorrow. He says he isn't going to bottom feed the juvies he has a separate feeding container that he will use. With that being said how safe is this substrate for juvenile axolotls? I've attempted to attach the photo of his tank setup so hopefully it shows in the thread. Thanks for any responses this I'd the best place I know to get axolotl help.

He should really hold off on the sand until atleast 5". Even if he feeds in a jar I guarantee they will eat sand. I've watched my juvies snap at bare bottom (no food) and my adult snap at the sand (no food). Juvies will also be eating bloodworms which is messy. Messy = floating out of jar/bowl and onto the floor. They will also smell the blood ( the red stuff bloodworms make when you cut them up, I don't know if it's actually blood :lol and snap wherever, which is what makes me think my juvies snapped at a bare bottom with no food.

I just think it's a good precaution as sand can cause impaction in little lotls. I never would recommend, and I don't think anyone is foolish enough to use gravel in an axolotl tank with a feeding jar or bowl. Its the same concept to me. It's just not worth the risk.

Juvies grow pretty quick so it shouldn't be too long until your friend can add the sand.

As for the separate container, if he's planning to catch them, put them in the container to eat and then back in the tank - he is going to stress the axolotls out too much. As mentioned above, bloodworms will go everywhere in the tank regardless if there's a bowl or jar. It'll be even messier with two lotls thrashing about in their bloodworms.