breeder basket

[MiamiCuse]

I have a breeder basket and all sides are transparent. The fries kept wanting to swim "down" but can't. I tried to put some gravel in it but those get heavy and the basket sinks.

I am thinking may be I can paint the bottom. Is this possible? Is there any safe non-toxic paint I can use that will work when submerged for a long period of time?

[NickFish]

Not sure what you are talking about. Why is swimming down a bad thing? That is a natural instinct for fry, they will always swim down and if it is painted even more so.