Using a MJ1200 on a manifold is a neat idea. I will have to use that on the 2 I have. I run Rowaphos in one and carbon in the other. said:
My manifold actually has 4 lines on it. 3 are meant for phosban reactors, and the 4th is a gangway valve (think that is the term anyway). I made it twice the width of tubing as the tubing going to the phosban reactors. I then open and close it as necessary to regulate how much water is forced through the 3 other valves (going to the reactors).
Right now I have the gangway valve fully closed so that all 300gph is going to the 3 reactors. Back when I had a Mag9.5 hooked up to it, I had the gangway fully opened.
I personally think that this extra line is necessary to truely regulate the flow through a manifold. I can take pics if anyone is interested.