Hi all: I live in new York city, and have a question about my water parameters. I have GH 60, KH 30, pH 6.5, no2 0, no3 20. I have all tetras and otos, various plants, nerite snails and a couple of shrimp. The issues I have seen: I’ve gone through periods where it is hard to introduce new snails or shrimp. They die quickly. I have tried to raise the water hardness a bit to be better for the plants and inverts without killing the fish. I was using a combination of epsom salt and calcium chloride, which is easily available at my local beer brewery shop. After killing a whole new batch of shrimp, I am revisiting my water parameters to see if they are not optimal. Any thoughts?