500 gal SPS tank questions

[Russ1]

I have a runaway monster! I need suggestions or advise regarding my 500 gal stony coral tank. The problems that I am having are too much calcium and alkalinity consumption. I would like to keep my levels at 400+ calcium and 8-10 DKH alkalinity but it just keeps creeping downward. I have a very large calcium reactor with a second chamber that is basically trickling into the sump. I also have a very large kalkwasser reactor that consistently drips RODI top-off water at a pH of 11+ into the sump. My pH stays at about 8.2 during the day and about 8.0-8.1 at night. I perform frequent large water changes with IO salt. My tank has about 3000 watts of lighting with a large fan blowing across the surface of the water so I don't think I can get any more evaporation. Thanks! Russ

 

[Travis1]

What is the PH of your ca reactor?? If the ca/alk is "creeping" downward than a small adjustment with the reactor may steady it out.