My pH is rising without me doing anything
got a quick question. How would a water pH be rising by itself in a tank? I am assuming something is leaching something into the water? But I can't figure out what it is. I have driftwood in the tank, java moss, slate and playground sand (all obviously rinsed well and the tank has been cycling for a few weeks now). The wood is still leaching tannins, but I didn't think that mattered. (ammonia 0, nitrite 0, nitrate 5ppm)
Any clues? I keep artificially decreasing my pH to around 6.4-6.8 because ultimately I want to move my tiger shrimp into this tank.
Any help is appreciated.