Hi, looking for advice. It’s a long one. I can’t seem to keep ghost shrimp alive and snails appear to have issues as well. I have a 20gal 2 year old established tank, heater at 76° 4 neon tetra, 3 (different species) corys & a Nerite snail One small stunted amazon sword plant & a piece of driftwood. The rest is artificial. If I keep too much light on, the tank gets that brown fuzz stuff. I experimented with veggies, but the white Cory was the only one eating them, she is a piggy and will eat anything & does good with her little algae wafer & leftover fish food. I had a lot of trouble balancing the ph, and wound up with very tannin water from the (boiled...) driftwood which I did not really like. Did a few huge water changes which raised the ph again. My tap water is about 7.8. Nitrite 0 Ammonia 0 Nitrate 40 Current ph 7.6 I have been adding acid buffer at this point. Which went really bad when I didn’t pre mix it recently & lost my serpae tetra & little nerite. 90% water change & QT in a bucket... lesson learned. I have, and do, also use distilled water mixed with my treated tap water (seachem prime) which does help. I really want this tank to support invertebrates, but the ph goes up when I add calcium (I had no idea the snail would actually snack on a people calcium vitamin!). I had to take drastic measures when he started trying to stay out of the water, did some reading in here & used super glue to fill his cone where his flesh was visible. I’ve been through dozens of ghost shrimp. Sometimes a few will last a month or longer, but most disappear within days. I do toss less than 1/2 a dose of plant envy in there about twice a month for my little plant. Again... has calcium. How can I add calcium to the water without increasing the ph?