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?

Do you have the actual python/waterbed filling attachment bit or do you have what I have which is just a T connector near the tap with a bit of hose and valve going to the drain?

The actual python system I believe uses pressure from the tap to create suction in the hose which sucks the water form the tank.

If you dont have this attachment then basically its just a big syphon. In this case you need to:

Fill the hose with water.
Open the "drain" valve the water should come out of the drain section of hose and pull water from the tank.

If this is not happening then it is either that the drain is higher then your tank or you have hose going upwards (ie a large loop in the hose). I found when I made mine (with no special connectors just a T and a on/off ball valve) that if my hose was too long (ie with coils in it between the tank and the drain) it would hold a sypthon. I cut the hose down so it is just the right length to go between my tank and the tap/drain and it works perfectly now.

The thing to remeber is that water doesnt like to flow up hill. If you have any part of the hose higher then the tank or any part of the hose going upwards any distance it wont work.

as the last guy said - the diy's are just a hose pipe - the pythons use a special adapter to create suction...

There is a post of mine in that thread somewhere pointing that out - but I got ignored

Unless your trying to move teh water up hill - you shouldn't need the suction anyway.

I have the t junction adaptor so shall i just block the extra hole then turn the tap on until water is coming out the other end into my tank (All the air has been pushed out) Then just turn the tap off and unblock the hole?

to start the syphon - yes

or just dont use the T, suck for a second and leave the hose trail into the garden to water the plants

I havn't got any plants lol. But yes i get the idea. Cheers guys