Calcium levels

[Davidw]

Having a lot of problems raising my calc levels. Water changes, adding Reef advantage calcium doesn't seem to have much effect. PH is good, Alk on the bottom edge, Mag is also low
Tank is a 240 been up and running about 8 months, 220 lbs LR, 2 in. live sand, 3in dead sand, 80 gal sump with live sand and rock. Most of the LR I believe, may have not been cured. I'm getting some coraline algae but not as much as I did in my 75 gal setup. I had a massive outbreak of cyno but I now have that under control with a phos reactor,
I have a pretty good size clean-up crew and adding a few more almost every trip the the LFS.
Is their a relationship between Mag and Calc?
Any suggestions will be appreciated.

 

[roshi719]

Yes there is a direct relationship between Mag and Calc. I would say start off by raising your Mag. If Mag levels are too low it is imposible to get calc into suspension, or keep it there if you are adding liquid.

 

[jtl2]

Another thought...I'd been a little worried about calc level in my tank 360mg/l measure by Aquarium Systems Reefmaster kit. Just tried a Salifert kit and calcium was 400mg/l (measured within minutes of one another). My alk and pH were also different with the Salifert kit. Also monti cap was growing all along so I thought the 360 number might be off.

 

[bellareef]

Some of the new Salifert kits (alk, etc) come with a reference solution, which would be helpful. As Roshi posted, 1250 ppm (or higher) Mg is necessary to maintain proper Ca and Alk, which is actually super saturated.

1250-1400 ppm Mg
380-450 ppm Ca
7.5-12 dKH Alk

 

[gparr]

Yes, Mg needs to go up for the rest to work.
Gary

 

[returnofsid]

I agree that it's a Mg issue. Low Mg will keep your Ca from being able to rise. Ca, Alk and Mg all work in relationship to one another. Gotta keep them balanced or one will throw the other off.

 

[aquarius77]

If pH is too high, say above 8.4 then you will start to get precipitation and no matter how much additive you put in you wont be able to raise it. You may not always see the percipitation in the form of a snowstorm, but the impeller shafts of your pumps will tell you alot. If they are geting crusted up with calcium buildup you may need to check your pH testing equipment as well as your mag levels.

 

[Letsgotothezoo]

Agreed with everybody here...

Also, get a ca reactor.....you got a big tank there.....

 

[H@rry]

Look at getting a calcium reactor. For a tank as big as yours, it will be much simpler to maintain your alkalinity. Maintain the alkalinity level between 7 - 11 with your CO2 bubble rate. Maintain your effluent pH levels between 6.5 -6.7 with your drip rate.

When you finally get it "dialed in", it's pretty much hands off, just weekly monitoring of alk and effluent pH.