Resolving Imbalance between MG, CA, dKH

[BSimm]

Hello folks and thanks for helping me with a bit of problem. I've read many of Randy's articles, but am at a loss with a recent imbalance and looking for suggestions.

Running a 105 Tall Oceanic, with a 35 Sump. Running a PM skimmer, filter bags and a three little fishes phosphate reactor. ALso running a PM Kalk reactor.

I started with Alk around 6.0, CA at 320 but MG was so HIGH... off the salifert charts (1700+). I think the spike in MG was due to Dosing it about 1 month ago, but it's hard for me to believe that's it's stayed that high from my dosing so many weeks ago, but I'm not a pro, so let me know if my thinking is wrong.

Recently (about 2 weeks ago), I began dosing (beyond the Kalk). Using Kent Marine Turbo Calcium and Kent Alk Buffer. I moved Alk to 9.5 but CA remains at 330. I've increased my Turbo Calcium dosing significantly and now I think I see some white precipitation collecting on the rocks (not cloudy water). I stared at 1/8 teaspoon/50 gal (3/8 teaspoon) a day without any increase in CA. So I eventually moved incrimentally up to 1.5 Teaspoon/Day... and BAM.. I see the white stuff. But after checking CA this morning.. still at 330.

My test kits are new, Saliftert.

Amm, Nitrite, nitrate=0
PO4=0
PH = 8.25-8.39 night/day.

I'm seeing no ill effects in my corals (mainly SPS dominated (about 15 small colonies and small frags) or my fish, Two tangs, two small clowns, a firefish, six line wrasse and watchman goby).

My questions... Will High MG negatively impact my CA numbers?
I've not done a water change in a few months..I have a feeling that would help my CA values (Oceanic Salt).

How the heck does one get MG DOWN? Or do I need to?

Anything else you need from me to help diagnose???

Thanks for brainstorming some solutions with me!!!

Brad

 

[Randy Holmes-Farley]

I started with Alk around 6.0, CA at 320 but MG was so HIGH... off the salifert charts (1700+). I think the spike in MG was due to Dosing it about 1 month ago, but it's hard for me to believe that's it's stayed that high from my dosing so many weeks ago, but I'm not a pro, so let me know if my thinking is wrong.

Magnesium is very slow to decline, so if you did overdose in the past, it may stay high until slowly brought down by water changes. Oceanic is very high to begin with, so it may never decline much.

In any case, unless it is a mistake and it is low, it is not impacting the calcium and alkalinity.

This is in your 24 gallon tank? If so, then to boost calcium by 50 ppm will take about 2.5 teaspoons of Kent Turbo calcium. So the amount required was not excessive, IMO, unless you added that 1.5 teaspoons for many days.

Alkalinity is 9.5 dKH, right, not meq/L?

Did you dissolve the Turbo Calcium in fresh water before dosing?

What is the tank pH?

 

[BSimm]

Thanks for Replying, Randy. I've not changed my signature info yet.. sorry.

I'm running a 105g Tall Tank.. with 35g sump.

Alk is 9.5 dKH
PH is 8.25 at night... nears 8.4 during day.

I have mixed in Fresh RO/DI in past, but then the last couple days I got lazy and mixed in tank salt water.

Hope this helps.

Brad

 

[Randy Holmes-Farley]

Ah, in that case you might need substantially more Turbo Calcium to make the boost.

I would not mix it into salt water, as that may cause precipitation of calcium carbonate.

is the limewater being added slowly?

 

[BSimm]

OK.. I'll add the Turbo Calcium into freshwater only, then add to the sump. I wish I understood why that makes a difference, since it get's added to the salt water eventually (as you can see, High School Chemistry was NOT my thing!!!)

The lime water is on a constant drip flow.. a drop about every 2-3 seconds.

Again, Thanks for the help, Randy.

Brad

 

[Randy Holmes-Farley]

I wish I understood why that makes a difference, since it get's added to the salt water eventually (as you can see, High School Chemistry was NOT my thing!!!)

Sure, that's why were here.


When you add 1 teaspoon of turbo calcium into fresh water and then into 100 gallons of tank water, calcium rises by 5 ppm, which cannot cause any issues.

When you add that same 1 teaspoon into 1/4 gallon of tank water first, then the calcium level there jumps by about 2000 ppm, which is enough to possibly initiate precipitation of calcium carbonate. It is the concentration of both calcium and carbonate (among other things) in the water that determines whether you will precipitate calcium carbonate. Too much leads to precipitation.