So my tap kH is 4 drops, my gH is 7 drops. My pH was falling so I added shell pieces to my canister filter and a second piece of cuttlefish bone to the tank. I had tried Amano shrimp before but they disappeared. At the time I assumed due to our thick lipped gourami ( since rehomed), but now I wonder if the border line kH could have contributed. So my kH and gH have not changed since the addition of the shells, but the pH has stabilized. So I assume the shells are working. We would like to try shrimp again but are the parameters okay? Ammonia = 0 (until a water change, tap water has 1.0, but my tank manages it within 48 hours), 0 nitrite and nitrate 5-20. Current inhabitants: 2 m guppy, 2 m platy, 2 honey gourami, 5 Cardinal tetras, 4-5 green aneus corys, 1 ABNP, 1 mystery snail, 6? Nerites. 34 gallons, some live plants.