It didn't seem to work well, and when I called for help with it, the lady said she'd have somebody call me back...I never got a call back....so the Python went back.
It simply didn't work well at all. It seemed that for every 4 gallons that I was dumping down the drain, less than one came out of my tank. So that would have cost me about 100 gallons of clean tap water in order to do a water chage on a 55 gallon tank!! Time is important, as you can't make it, save it for later use, or buy it.
Personally, I'll reccomend a garder hose siphon. My tank is in the second story of the house, so I have my wife hand the hose up to me through the window and do it that way. The second story drop makes for an awesome suction. A cheap garden hose will actually flatten out due to the suction power. Even at that, it blows the Python away, and doesn't waste clean water from your tap. I got a better one and havn't tried it yet, but it should be even better.
It takes me about 1/2hr to do two 55 gallon tanks and one 30 gallon tank...and that's with the cheap hose flattening out, which restricts flow some.
So, I'll compare:
Python time- so long I gave up after about an hour
Hose time- 30 mins
Python cost- $70 (50ft version)
Hose- $20
Not only all that, but the garden hose can be used to wash the car or water the lawn... try that with a python and see how well it works!! 


