DrBDC
Active member
It depends on what the IO tests at. Is it the Reef Crystals version? I believe it is higher in mag than the standard IO is. I have to bump my IO by about 150 ppm. But whatever it is, a 50% water change only gets you half way between the two. Another 50% gets you 75%. So water changes can take awhile to do it.
What is your total system volume. I have some MgCl and might be able to help you out.
What is your total system volume. I have some MgCl and might be able to help you out.