Yesterday morning when i tested my waters in my 29g i had 5ppm nitrates. I added a new filter to my tank, a rena xp2, but i left my crappy aquatech HOB filter on and will for a few months until i build bacteria on the new filter. When i tested my waters today when i got home from work i had 0ppm nitrates. Is this a problem?? I'm going to assume no because i have 0 Ammonia and 0 Nitrites.