Ca too hight Mg to low. how to correct this?

i just bought some salifert test kits. i got the Ca and Mg kits. i tested the Ca in my tank and it is well above 500ppm. i dont dose with calcium or really anything for that matter. i did use purple up in the begining. but havent done so in 6+ months. my Mg is 1170ppm. the Ca in the top of water is 30ppm. what can i do to bring the Ca down to levels around 400-450ppm? what role does the Mg have on Ca. salinity is at 1.0255. using a hydrometer.

 

"the Ca in the top of water is 30ppm."
Not sure I understand this right. How is the Ca 30ppm when you say it's also 500ppm and too high?
Add epsom salt or a mag sulfide/mag chloride mix to bring up the mag to around 1400-1450ppm.
What's your Alkalinity at?

 

water from the tap has 30ppm Ca. i dont use RO. i live in van city canada. water goes from a water shed. alk is always around 160-180ppm. if i raise the Mg will the Ca lower?

i first tested the Ca in the tank and then i tested the source water to see if there was any Ca in it.

 

Ca, Mg and alkalinity have a ratio that they should be in, one depends on another and so on. I used Mag. chloride to raise my Mag up, any store bought product should work. If you want to lower the Ca quickly, you can do a water change, if not, any hard corals/snails will use it up eventually, it depends on what you have and how much.

 

The first thing that you should do is to get your Mag to 1400-1500ppm. Once you achieve this, everything else will stablize. Cal and Alk are opposites, when one goes up the other goes down. Mag helps to stablize the elements. I f you need to lower your Cal, just raise your Alk slowly. Luna

 

what the highest that my kh should be? it is around 160ppm. anyone use these selifert kits? they aint cheap!

 

I keep my DKH between 10-14, you shouldnt go over 16. Luna

 

what does that convert to as ppm?

 

I dont remember buddy, hopefully one of the experts can chime in and give us the answer. Luna

 

Here's a link:

OZ REEF - Alkalinity Conversion

160ppm / 17.86 = 9 dKH