Posted by a reviewer on Amazon

I filled it by holding one end against opening of a streaming tap and letting water flow through until all air bubbles had disappeared

Posted by a reviewer on Amazon

The water level responds to changes in a couple of seconds or so but not so rapidly that it overflows at the slightest provocation just needs checking for air bubbles and kinks

Posted by a reviewer on Amazon

At first i was going to buy some clear hose from bq to do the same job until i worked out that just the hose would be over £30

Posted by a reviewer on Amazon

Then remove every air bubble by tapping and lifting and put on the caps and you are ready

Posted by a reviewer on Amazon

If you have a large area and need to get a perfect reference level timber floor wall plate steel beam footing sleeper wall patio drive underground drainage etc you neednt waste your money on a fancy tripod laser

Posted by a reviewer on Amazon

I slightly re engineered mine after watching a how to video on youtube which basically replaces one end for a tub to hold the water the tub stays still on an elevated table while the other end gets fastened to a length of wood hold the length of wood with the tube upright on point a and mark the wood where the water level has settled then move to point b with your wood and pipe and see weather the water level has moved up or down from your mark if its gone below the mark by say 9 you then need to dig down 9 to get to the same depth of point a

Posted by a reviewer on Amazon

If done properly and you dont have any bubbles in the tube point a b should be exactly the same depthlevel

Posted by a reviewer on Amazon

Filling the tube with water was not a problem with a small jug but to make it work accurately you must get the bubbles out