Removing UGF from cichlid tank.

any1 know the best way to effectively remove a UGF from an established cichlid tank?

it will be on my 55g, and the UGF has power heads if that makes any diff.

i would think the best way would be to do a partial water change while taking out one filter plate. and then repeating next week on the other plate.

i hooked up this reverse osmosis mechanical filter (not the RO unit) just the micon filter part to a powerhead so it would continuiously filter out the old dead bacteria, while doin a water change also with all filters running at full throttle, it took about 20 minutes to do and there was tons of stuff under the filter plate. during the filtering and changing the water got so dark tat u couldnt see any fish!!!!
After about 6 hours of the RO filter and normal filters still goin the water is still kinda murky.