If yourbudget though, and as long as you dont mind a bit of work every now and again, stick to the 50% water changes every week or two weeks, yes its a bit of a pain, the easiest way is to get a 10 meter hose pipe shove it in your tank, put the other end out of your front or rear door suck on the end to start the syphon and drain the 50% away, Also if you have an upstairs bath tub, the night before you do the water removal, fill the bathtub with watyer leave overnight for the chlorine to dissipate, then refill your tank by putting the end in the bathtub weighted down, so it doesn't flop out and the other end suck syphon into your tank. till its full. I know its a bit of messing about but if your on a budget its a reasonable way of keeping a clear tank with minimum layout.