spend about sixty bucks on a ro filter, ebay. a sixty dollar ro filter will produce about twenty gallons of water a day. my ph is between 6.1 and 6.2 straight from the filter. its pretty much a must for hydro. your plants will definitely like you for it. also pick up a tds and ph meter, some are as cheap as twenty five dollars. i never use ph down, ph up is a different story, especially during flowering.