520 on the cal isn't that bad, but 6 on the alk is...as mentioned stop dosing the cal and slowly bring the alk back up....if you don't want to use the alk part a cheap alternative is baking soda which is what I use..I can send you the reef calculator to determine the safe amount to use....
Thanks mike yeah everything was going great until a few days ago when I finally tested my cal I was wondering why my alk was not bumping up proably because it couldn't with cal that high !
I made a rookie mistake and let the tubes from my 2 part touch the water they clogged !!
I duct taped my doser tubes to the rim on my sump about 4 inches about the water. It gets some salt creep and build up, but i just pour some RO water on it and rub between my fingers twice a week when I'm cleaning skimmer, changing filter socks etc.
I would suggest you dont stop dosing cal all together with the 2 part. This might lower you cal to quick when dosing the alk part. I would do like 4 parts alk to two parts cal to keep the cal from bottoming out when adding large alk amounts. Or at least check your cal every time you add alk or you could be in for a Rollercoaster ride.
Just checked my alk has gone up a tad cal came down a tad so as of now I'm at least going in the right direction ! Will test alk and cal 2 times a day till issue is solved!