I don't like massivore, it stinks and makes a mess. Plus I personally think there is too much protein in it. Plecos eat alot as it is so when you're feeding them something like massivore, they will get overweight real quick which I don't think its a good thing. NLS is one of the best things you can feed your plecos. Make sure its the NLS THERA A.
Just look at the ingredients:
Ingredients: Whole Antarctic Krill, Whole Fish, Whole Wheat Flour, Ulva Seaweed, Chlorella Algae, Garlic, Beta Carotene, Spirulina, Omega-3, Alfalfa, Mollusk, Fruit Extract, Vegetable Extract, Vitamin A Acetate, Vitamin D Supplement, Vitamin E Supplement, Vitamin B12 Supplement, Niacin, Folic Acid, Biotin, Thiamine, Riboflavin Supplement, Pyridoxine Hydrochloride, Calcium Pantothenate, L-Ascorby-2-Polyphosphate (Stable C), Choline Chloride, Ethylenediamine Dihydroiodide, Cobalt Sulfate, Ferrous Sulfate and Manganese Sulfate.
Can't go wrong with that.