Algae under substrate

[alyrchd]

My substrate was filled with GHA, so i took the superficial part out and washed it with hydrogen peroxide
I know that kills good bacteria too, but nothing else was working
Anyways, when i put it back into the tank, a bit of the algae that stayed got buried
Is that a problem?
Will it die and turn into more nutrients?

Besides that, does anyone have tips on how to get rid of algae on the sandbed as i’m almost sure they will return

 

[blaxsun]

Get some sand sifters for your cleanup crew (conches, cerith and nassarius snails).