I normally would do EI Dosing with dry fertilizers(KNO3, KH2PO4, and Plantex) and change 50 percent once a week. I have college starting up and i work 30 hours a week. I sometimes dont have time to do my 50 percent change every week. Is there anyway I could get away with a water change every other week? Its for my 20 gallon tall. Anyone have a dosing schedule with a similar tank that only changes water every 2 weeks instead of every week? If so, please share. I'm open to all suggestions.