The best substrate for your bristlenose...

i used to have bare bottomed tanks but was losing L066 fry to a bacterial build up which was coming from base of tank even with daily water changes & now have a sprinkle of sand along the base just enough to cover & have lost no fry since, As i keep alot of corys as well it has to be sand for me

So i was thinking about using sand as the substrate since i thought maybe the BNs would like to dig around in it, but now i guess not? I don't trust myself with the chopstick idea. Are they fine on just bare bottom? Or should i have gravel? In my 20 gal i have gravel and plant mix for the substrate but in my 75 i have bare (turtles and koi fish plus gravel seems a little annoying for cleaning?) but i haven't been doing fish long so i'm not sure which would really be better? Right now i have a bare bottom breeding tank planned but if people think gravel will help i'd get some? What size gravel is best? Thanks!

honestly, sand is not as bad as everyone makes out. I have sand in all my tanks. The trick is not to get the really fine stuff. Beach sand for example is way to fine where as pool filter sand is fine.