I read the thred on making a DIY Python for water changes. I bought the hose and all adapters but I cannot seem to get the suction going. I turn the tap on for about 5 seconds then off, i have also tried leaving the tap on for my gravel vac to fill up (Getting rid of any air in the pipe) And this didn't work either. In the end i just gravel vacced like usual and just used the hose to refil. Anyone know where i'm going wrong?