ok the pump has been running for a couple of hrs. BOy is it quiet compared to the old one! Going to leave it on low all night and see how the water looks in morn. I did vacuum to waste (it vacuumed on low!) but the water is hazy since I scrubbed all that green residue from walls. Oh I had another question. We put 300lbs of sand in the filter but my husband said it was between 1/2 and 3/4 full. Is that normal? our 2 old sand filters (200lb) were more than 3/4 of the way filled up......