I don't like the PH's that are in my tank right now but I'm not sure yet, how to remove/replace them and keep enough flow. I hoped that I could use the SCWD to alternate flow from my return pump and make do, but I don't get enough flow from my pump now to remove the PH's. I'm leaning towards adding a closed loop to take care of the flow issues, but that is also more hardware. *sigh* What to do, what to do.