Hello, again, Another question if I may. My system has been cycling (fishless) for about three weeks, and doing very well. It is pulliing my ammonia levels down well, nitrates are low, and nitrates at about 50 (need more plant load).  But I keep adding chelated iron almost daily to get the level up to about 0.5, and the next day it is usually down to 0.2 and in twos days almost gone. Is there som…