I have 3 very small African clawed frogs in a 20 gallon tank, which I will upgrade to something larger when they start outgrowing it. In the meantime, the diatom (brown) algae is phenomenal & out of control. I have a small sponge filter in the corner of the tank & a larger canister filter was recommended by a different group. I have limited funds & have also read that frogs are super sensitive to the vibrations of the filter. Nerite snails eat their weight in gold in my fish tank but I hesitate to put them in with my frogs. Any suggestions are appreciated. I do regular water changes/vacs & don't leave extra food at the bottom of the bare bottom tank. There is also java fern floating around in it. The water isn't necessarily dirty or cloudy but the froggies give off a very distinct odor & the algae is covering everything in the tank.