I cut the closet flange and tappered the end so the cap would fit down in it,then siliconed it in place. I then used a 4" piece of pvc to build the chamber, and installed a cap on top. The pump is a mazijet 400 which is really to big, a 250 would have been better, but I added a valve on the discharge and have it turn down about 3/4 closed. I ended up using a brass valve and a few brass fittings to install the pump, it was all I could find in the size I needed, I think the brass will be ok since it's DI water with a bit of kalk. The only thing I'm having some trouble with is the clean-out, it is hard to get to seal and I have to use teflon tape and still tries to leak, I looked for a clean-out with a gasket but was unable to find one.
The last pics shows a relay, I plug the two aqualifter pumps into the outlet and then the black wire plugs to the PH controller and the white wire plugs to the JBJ top-off. normally the top-off will go thru the reactor but if the PH ever reaches 8.5 the relay will switch over to the fresh water pump and only top-oo fresh water. The reactor is set up on a time that comes on twice a day for 30 min. to mix the kalk, during that time and for about 45 min. after the JBJ is turned off by a seperate time, that way I'm not topping off with kalk until it has a chance to settle some. my ph was running at 8.2 in the morning to 8.4 before lights out, now it starts out at 8.3 in the morning, so if the ph is at 8.2 in the morning I'll know it's time to recharge the reactor.