Your PH is fine at 5.5. It maybe the h202 that's making your water murky. A little dose to my bro's did the murky thing but we were fighting rot before a complete change and wash down of the systems. Just used it to be sure. If it changed the ppm's it would not be enough to notice. We are doing a test run for a fog log with fog misters.

The calmag would only give it a tinge of color like some nutes do.