Newbie questions

[I must be batman]

How many powerheads would I need for a 45 gallon? The tank came with two, but I'm worried that would be too much current.
Also, my new pleco doesn't seem to get that those algae thins are for him and when he's suckin on glass his stomach seems sorta caved in. Will he figure it out or should I change brands or what..?

 

[HUKIT]

What other forms of filtration are you using? If your using the powerheads for circulation depending on size I think one would be enough.

As far as feeding your plec, I feed mine one hour after the tank lights are out. I also feed in the same spot every night to train him where to find the wafers.

 

[Homedog98]

Zucchini works too if he's picky.