Sorry, I know I've been posting a lot of questions here...

I have some ACF tadpoles that are disappearing. I had probably 50-100, and now it looks like it's under 20.

I have two questions. First, are these cannibalistic? I know this is a problem with pacman tadpoles...
Two, I used methylene blue to prevent fungus on the eggs, but I may have added a bit too much. Could this cause the tadpoles to die off?

These are the only things I could think of. Water parameters are fine.