I just had my pool opening today (in-ground, DE filter). My water is dark-green, as it usually is when opening. Is it normal for me to have to backwash my filter & change my DE every hour while he water is this dark? It seems every 45mins-1 hour, the PSI gets high (or gets extremely low as the pump isn't drawing much water). Back washing fixes it, but then I have to do it all again every hour. I just want to make sure this is ok & that I'm not hurting anything. Thanks!