So I've had a 20g qt running for 25 days. I'm constantly doing water changes because it seems the hob filter does nothing. I constantly have waste just sitting at the bottom of the tank and I don't over feed imo twice a day small amounts. And i bought an oversized hob for this sized tank and makes no difference.. do I need to place a powerhead to get it to move around to be sucked up by hob? Here is a picture just 1 day after water change and I vacuum up the bottom every time..