Pleco's don't "eat algae", they eat a specific algae. The have to be fed wafers.
I have Rams snails, pond snails, an apple snail, mystery snails (trapdoor less) and MTS. My tanks have 1tsp for 1g or 1 TBSP for 5g (according to if I mix up 15g of water at a time, then I use the 1 TBSP). All snails are fine....anyone need MTS...I'm overrun!!!
Are you sure you have algae? There are several "algae" that are not algae at all, it is bacteria/fungus. Each algae eater eats specific type of algae.