I wanted to have a go at building myself a reactor so I thought i would have a go at doing it with parts available from the high street. Here is a list of what i needed and the cost. 1m of 1.1/2" waste pipe Â£3.82 2 of 3/4"x1.1/2" overflow reducer Â£1.75ea (this needs a compression fitting on one end with1" thread) 1of 1.1/2" 90dgr bend solvent weld. Â£1.72 1of 1.1/2" access plug solvent weld. Â£1.90 1of 1.1/2" sweep tee solvent weld. Â£1.90 1of 1" connector (pond pump fitting)blk Â£2.40 1of 1" hose connector (pond pump fitting)blk Â£3.19 clean all of the solvent weld fittings well with the correct cleaner and apply the adhesive, you wont have long so dry fit it all first so you know where it all goes and that it all fits. put PTFE tape onto the hose connector and screw into the 1" connector and using 2 adjustable spanners do it up tight. screw this onto the overflow reducer( I found 2 O rings to go on these to make a good watertight seal) be careful not to weaken the solvent weld joint. thinking about it now you could do up all the threads before gluing the joints. I then drilled a 6mm hole through the bend (see next photo) and inserted some 6mm rigid air line i had, this was glued into place. it is all now being left to let the glues harden before i do a water test.