Python manufactures this truly unique system. Makes water changes easy, designed to drain and fill aquariums plus use as a gravel vacuum. No need to carry heavy buckets of water to and from your tank, just hook this up to a faucet and siphon out water and then fill with fresh. Kit includes: hose, gravel tube, switch, faucet pump and adapter, and hose connectors. Available in a variety of sizes; just measure the approximate length from your tank to the nearest sink and order the size that's best for your set up. The Python Porter keeps tubing coiled properly when not in use, water/mildew resistant.
That is the excerpt from Petsmart. Boy would it be great to not have to carry buckets of water like I am now!!! One question though, if you can fill the tank back up with it, how to you treat the tap water before it goes into the tank?