Make that 4 aussie's mate! :lol:
yeah i made my own python style set up too but its easier and less wastefull if you just run a long hose outside int a pond or garden etc...
just remember not to step down the diameter of hose from the gravel vac to your 15M hose otherwise your waterchange will be Very slow!
in an emergency i used a 10mm lil' garden hose and it took like F'n 45mins to do a 30% water change
+ the lower the hose is outside tha harder it sucks, i used to put mine in the lowers part of the garden and my waterchanges were like 10mins faster per tank :thumb: