Okay, just recently moved and set my tank back up here at the new house. I changed all the substrate from aquariumplants.com. 3 pieces of manzanita and some large pieces of seeded filter foam were kept wet and submerged in a 1 day move to a temporary tank, where i kept the fish and plants. Now that i have the tank set up and its been almost a month, I added a ph controller for my c02 and notice PH crashing. Out of the tap, PH is 7.6 KH 5-6. Now over the course of a few days, my PH is down to 5.5-6. KH is almost non existent. I didnt have this problem with the old setup before I moved. What is eating up my kh causing my ph to follow? Is it the plants? which right now are primarily root feeders. Or could it be the nitrification process trying to get going? I dont have a test kit right now, but I had a few strips with nitrite and nitrate on it, nitrite was about 5, and nitrate was upwards of 20-40, and I have been dosing my ferts so I wasn't shocked about nitrate. What worried me was a nitrite reading from the test strips, not exactly accurate but its something.
Ive never came across this problem before, how should I go about keeping my kh up and stable? It seems to be dropping almost 2 points through a week. 150g with a 50g sump. If my cycle hasnt finished the ph alone keeps it from continuing if its dropping so low correct? Though im not as worried about the cycle in a planted tank. The ph drives so low that my controller never turns on and Im not getting c02 in the tank.