I'm just starting an EI dosing program on my Rio 180 using dry ferts, so i shall be doing a rather large water change every week. Normally i change probably about 15-20% per week at the moment, by using a gravel cleaner with a hose and fill a bucket a few times, and then add treated water with a large watering can. Probably a bit antiquated i suppose. I would be very interested to know what other people do with their water changes, how much, what equipment is used, any DIY methods used etc..... Basically i need a much more efficient method to do a 40-50% change each week. Is there something i can buy or maybe make that will help? What do you all do?