Ca and Mg doe no decline

joducus · Feb 9, 2015

Hello,

i have problem and i cant help myself.

I have 200l tank, frag 10 pc sps, 8 pc lps.

I run all Red Sea program.

Value:

Ca 460
Mg 1390
Al 8,6 dKh

Salatine 1,025

3 weeks i dont change water, but my level of Ca and Mg i still SAMe VALUE, does not decline....

only decline Al and this Al I keep cca 8,4 dKh.

Please someone tell me why my Ca and Mg have still same value?

I have redsea and so salifert test.

Thanks!

saltyphish · Feb 9, 2015

How do your coral look?

joducus · Feb 9, 2015

looks good...but dont grow...or grow very slowly...but dont die...

maroun.c · Feb 9, 2015

Are you sure your test results are correct?

joducus · Feb 9, 2015

yes i am sure...i use red sea test and for control i used salifert test....the value is +/- 10ppm the same

joducus · Feb 9, 2015

I dont understant. 4 weeks i didnt dosage Ca and Mg a value is still same..

Randy Holmes-Farley · Feb 9, 2015

When alkalinity declines by, say, 1 dKH, the expected decline in calcium is only 7 ppm and the decline in magnesium is much less than 1 ppm.

So it is likely that you just do not notice the decline of calcium and magnesium since your salt mix is providing so much more than natural levels anyway. In a low demand situation with a salt mix where calcium and magnesium are very high, you might never need to dose those.