Why wont my calc and mag drop?

steallife904 · May 17, 2017

So for months now my calcium has been 500 or higher and I tested it with 3 test kits and my LFS, the magnesium has been 1470-1500 with 2 kits and LFS. I am not dosing either one just doing about 5-10 gallon water changes a week (150 gallon system). I was dosing before but turned the doser off and am not dosing anything now, haven't been for months. My ALK was up but has been falling slowly and is currently 8.7 DKH (trying to get to 8). I think I should have my calc closer to 420 and mag 1380-1400 but the calc and mag will not move???? Any ideas?

Corals have not been happy, part of the reason I am trying to get my levels back the where they where in the past when tank was thriving (pre baby

). I have also been dosing neonitro and neophos very little to bring my phos and nitrate up a bit from 0.

Randy Holmes-Farley · May 17, 2017

The calcium and magnesium values are fine.

If alk is not being supplemented, calcium and magnesium won;'t fall much.

For each 2.8 dKH drop in alkalinity, calcium will only drop 18-20 ppm and magnesium maybe 1 ppm.

steallife904 · May 17, 2017

so just stop dosing anything until my ALK drops down to 8 where I would like to keep it and not worry about the high calc and mag? I guess once my ALK gets down to where I want it to be and I need to start dosing for it again then the calc and mag will adjust.

Will ALK or CALC change at all while I am increasing my Phos and Nitrate?

Randy Holmes-Farley · May 17, 2017

steallife904 said:
so just stop dosing anything until my ALK drops down to 8 where I would like to keep it and not worry about the high calc and mag? I guess once my ALK gets down to where I want it to be and I need to start dosing for it again then the calc and mag will adjust.

Yes.

steallife904 said:
Will ALK or CALC change at all while I am increasing my Phos and Nitrate?

Not directly and not likely very much if at all. If corals are actually starving they may grow faster and may use more alk/calcium/magnesium.

hatrix11 · May 17, 2017

With all these parameters changing, and as you stated your corals aren't "thriving". They may be mildly stressed and not consuming calc alk and mag as much.

steallife904 · May 18, 2017

So if i shouldn't worry about dropping the calc and mag right now and i am not dosing ALK (will let it fall on its own back around8dkh). Should i try to do anything else other than increase my Phos and Nitrate which have been 0 forever? Just trying to get my tank back on track and so far its beating me.

Next thing i can think of is lights and flow which i know can vary person to person. I have 2 Gyre 150s, one on 50% and the other on 40%. I have them set on my apex to only run 1 at a time for 30 minutes, when both ran at the same time it caused all the corals in the middle of the tank to peal back and sand to move in the middle. I have a 50 reefbreeder photon V2 for lights and a 2 bulb retro t5 (only run 1 hour mid day). LEds come on at 10 AM (low power) - and off at 10PM, i only have them powered higher than 35% for 4 hours from 1-4, slightly lower at 12 because T5s are on. Run mainly blues higher and whites lower because it looks better to me. Been afraid to turn up any higher for fear of cooking corals that where already stressed. The LED is somewhat new (got in march) but had the photons V1s before and had them running when tank was thriving, plus issues started before the light switch.