I think that all really depends on a lot of factors. 1) are you doing water changes (shouldn't be doing this much if you're battling dinos anyway), 2) how long you're dosing, 3) How much is being consumed by the diatoms. I totally get not wanting to buy yet another test kit, however, I know I took a risk by only eyeballing it and going off of other's previous dosages. I don't personally know of any issues associated with silicates other than diatoms. I would say if you're going to do this without a test kit, its a "do at your own risk" sorta thing, but should be fairly safe. If anyone reading this is a marine biochemist please correct me if I'm wrong.Yeah I don’t want to buy another test kit. So maybe just do like 15 drops a day or something? It’s not gonna harm anything?