Mg rising Ca dropping.

Fisherman Joe · Jul 10, 2015

Hi all.

Finally got my dkh stable at around 7.7 - 8.0 but my Mg is rising to 1500 now and my Ca is dropping to 380.

How do I best address this long term please?

Randy Holmes-Farley · Jul 10, 2015

What are you dosing?
What salt mix and salinity?

Fisherman Joe · Jul 10, 2015

Using DD salt and it's at 1.025.

Not dosing anything ATM. Just have a calcium reactor.

A few weeks ago I did dose my Mg up with Red Sea foundation mix C.

Randy Holmes-Farley · Jul 10, 2015

What did you put into the reactor? Any dolomite?

A significant magnesium rise is either testing error, or coming from the reactor, but I suspect the testing.

How much is magnesium rising? A 100 ppm rise in magnesium would necessarily be accompanied by a 23 dKH rise in alkalinity, even if it were pure magnesium carbonate.

Fisherman Joe · Jul 11, 2015

I dosed my Mg up from 1300 to about 1400 a few weeks ago. It's since risen to 1500.

Going to do a water change. Dose my Ca up a little and add more Ca chippings to my reactor. Sound good?

Not sure if there's any dolomite in my reactor.

Tested 3 times and all three tests say 1500 Mg.

Randy Holmes-Farley · Jul 11, 2015

Magnesium cannot ever rise on its own like that. Either you added enough to get to 1500 ppm, or it was testing error. Maybe the 1400 ppm was the error.