juz check my water parameters today, realised tt my ammonia had gone up slightly by 0.5ppm... is it becus i added the UVC tt's y it causes tis problem?? becus tt time when i fix my UVC, i off my sump tank for abt 2 hrs so i was wondering whether is it tt the BB in the sump all died tt's y lyk tt.... but in tt 2 hrs my air pump is still on in the last compartment where the i put my powerhead.. hope someone can give some advice... so far aro and tankmates eating well