Elegant, simple and extremely well-functioning siphon system for cleaning the bottom and bottom layer. Now you are free to suck in a hose and get aquarium water in your mouth .... 3 squeeze the rubber pump and the water runs completely by itself!
There is a stopcock for adjusting the water flow, so you do not suck sand up through the funnel and for the more dexterous osse 'the possibility of extending the hose or connecting the submersible pump.