I know algae blooms come from a variety of things, so the process of elimination is what you do. On my tank it is coming down to nitrates....I think. I got new bulbs, cleaned my filter, and replaced the sponges, good water flow. I have no phosphates, but i am seeing 10 to 15ppm on nitrates. So now i wander how accurate my readings are. The algae lives on nitrates right? If i could take out all the algae, then test my water again would i have a higher reading then with the algae in it? It makes sense to me and becouse all i have is a canister filter with no nitrate absorbing stuff, and LR and sand then i dont have a way to get the nitrates out of mt tank besides PWCs right? If thats the case what would be the most effective Nitrate sbsorbing animal, as i have not got much floor space. I can get nitrate clams, and i think they are called flaming, or fire scallops. I dont want to put macro in my tank. Also how many would you need if your 45gal. tank always reads 10 to 15ppm of nitrates? I have a refugium(reef master 200) but its for my 90 gal. and it will be set up as soon as i get my lights for it, and its to big for a 45 gal. tank. Any ideas out there?