[petski2]

Hi all,does anyone know the best stuff to use for sealing the large screw on cap on top of my 650 ltr tank.I want to turn it over and use as a flat tank to give us better access to the hose reels etc.
Thanks
Pete

[EZclean]

Screw it on tight with ptfe tape. Then silicone gun round.
Semi permanent.
It will need another connector fitting so you can fill it up.

Best thing would be to swap it for a flat tank 

[mark dew]

How are you going to fill it up?
If drilling a new hole, then mastic or silicon will seal the lid.
Otherwise, you will be filling it up to around 2/3 of its volume.

[d s windowcleaning]

aqua seal what they use on fish tanks is good stuff .

[Nathanael Jones]

Put it in the buy & sell section for a swap. You might get lucky & it'll mean a whole lot less hassle.

[petski2]

Sorted thanks guys.
Silicone sealant

Pete