I’ve had the same, started out with just a few big bullfrogs and now have LOTS of tadpoles.
Have seen the tadpoles on filament algae a bunch, I think they could be eating it. My wife loves seeing the two big bullfrogs by the dock and I like hearing them.
And I definitely like eating frog legs! So far the bullfrogs at this pond have been off limits due to the wife and grandkids which is fine.
I’ve got plenty I can get after and do over at the other farm on our wildlife ponds. If these ever look over crowded I’ll thin them out. I like that the bass might eat some.