I saw where u can buy a water change kit but I see it's expensive and basically a gravel vac with a sink adapter and a larger hose. Has anyone successfully made their own who would like to share some pointers. I guess a very important piece will be getting the right size tubing from home depot. Wonder if anyone has had any success making their own siphon part? Also I have a pwerhead from an unused undergravel filter. Wonder if I can use that to create a power vac(but woould that suck up my gravel?) looking to do it right but also as cheaply as possible with doing it right.