Calcium reactor and two part dosing help

[Fish drive me crazy]

So I have a friend who crashed his tank every few months as far as his sps goes it RTN's so we tested his water and all the levels are in check cal a little high at 480 alk 9 and mag 1350 and phosphates pretty much non existent. I had only two thoughts one he has a 180 with a gyre running only 40% and two mp40s running on wave mode at 30 or 40 percent so one possibly so lack of flow and two I noticed he's running both a calcium reactor and a two part dosing set up which i haven't heard or anyone doing so I was leaning more towards the two dosing methods being used at the same time causing some kind of issue. Any info on the subject would be great thanks

 

[Randy Holmes-Farley Verified Community Expert]

Plenty of people use a reactor plus a two part or a reactor plus limewater, so that is no concern (and I can't think of any reason it would be).

How often has this happened and how long has the tank been set up?