Its your tank so u can do whatevs. But dude you have 40g. Thats alot of space, Idk how much algae your growing but I have. Stiphodons, Algae eating Loaches, Algae eating shrimp, A large False Siamese algae eater, Algae eating snails. And there is still plenty of algae to go around. My whole backwall is covered. Also if its an ART(Asian River Tank) those snails violate ur title :evil_lol: