Help needed! High Alk, low Magnesium, low calcium!

[Pulsing Xenia]

I can't figure out what's causing the high Alk, low Magnesium and low calcium.. Snails dying off, corals shriveled and not extending fully.

Any feed back will help!



75gal DT
Sump 30gal
2 ai prime hd lights at 60% 3hr ramp


Ph 8.0
Ammonia 0
Nitrite 0
Nitrate 0

Alk 11
Calc 330
Magnesium 1000

Running a filter sock, skimmer, and live rock in the sump.

Thought it was the salt having issues, maybe a bad batch? I was using reef crystals aways getting decent parameters from the mix. I would do about 15gal water change for the past 2 weeks and I can't stabilize alk, Calc and magnesium.

Changing to fritz pro mix. Mixing a batch now for a water change.

Any insight would be greatly appreciated

 

[Jr'sReef]

Bring up your mag slowly no more than 100ppm per day till it hits 1350

This will make your alk and calc easier to balance and maintain. By keeping Mg in that level 1250-1400 roughly, it will allow the calcium and alkalinity in the water to stay in solution thus helping it stay at the levels we want. Once Mg drops below that your calcium and alkalinity begin to swing because it will precipitate out of solution. Usually you will see the precipitate residue on your heaters and pumps. This is the short version but they are great articles online and on this forum. I believe by Randy explaining it all in further detail

 

[Pulsing Xenia]

Bring up your mag slowly no more than 100ppm per day till it hits 1350

This will make your alk and calc easier to balance and maintain

Thanks for the reply.
Water changes Or dose?

 

[Jr'sReef]

Water changes will help but dosing Mg will help you give it the boost you need. 15gal on a 100 gallon system isn’t really that much as far as for correcting the parameter values you need to get to. It will help more for the die off etc you may be experiencing IMO more than anything