I built this for a Knop C that we used on the 125 gallon tank we had. I added this second chamber to increase the calcium and also raise the pH of the effluent.

I first built one with male adapters on each end with threaded plugs in them that I had drilled and tapped for the hose barb fittings. I tried everything to stop the male adapter & threaded pipe plugs from leaking but was unable to.

I then built the one you see here and it worked for years with no problem. I used 2" PVC pipe to build it.

I put a 2" PVC coupling on one end and a 2" PVC union on the other end.

I glued a 2" PVC pipe plug in the open end of the coupling and the union. I drilled a 7/16" hole in each 2" PVC pipe plug and tapped it with a 1/4" pipe tap.

I put hose barbs in these 14" tapped holes and all that was let to do was mount it.

I used plastic pipe hangers from www.aquaticeco.com You can get the hose barbs x MNPT and the pipe tap and drill there also.

(Click here for a picture of the parts.)