Where did my fertilized N/P/K go?
So I am trying to start a new 75g tank. Filled with treated tap water, hooked up an XP1 and an XP3, threw in some Anubias, and then added NaHPO4/KNO3 (~ 1:6) into the tank. After a few hours tested the Nitrate = ~20 ppm and Phosphate = ~2 ppm. Added Seachem Flourish as instructed on the label.
In a few days plansts are beginning to decline quickly. Testing shows both N and P are down to almost 0 ppm. I added NaHPO4/KNO3 (~ 1:6) again. No improvement. All plants died or at least looked so. The N and P are again down to very low level.
What's going on? There seems to be a black hole in my tank that sucks all the N/P/K fertilized.