Calcium/magnesium

[pat8you]

So i was looking at some guys massive frag tank yesterday (probably 5' x 10') and i was asking him how his calcium reactor worked. He explained and said that he also put in some mg media in there so it keeps both ca and mg levels up. My question is can you overdose a tank on either of those? Or does the reactor just keep the water at saturation level?

Pat

 

[tamra&steven]

you can overdose it takes time to set one up but the reactor does not raise the level. just keeps them the same as what the were before the reactore was set up so the dontdrop. the more co2 you put into the reactore the faster your media melts and the higher you leves will be coming out of you reactor.

 

[pat8you]

so you can change how much ca/mg is in the water by the amount of co2 flow?

 

[ccCapt]

I never heard of anyone adding mag to a ca reactor. Aragonite is the ca reactor media, which needs the low pH provided by the co2 to begin to disslove. Aragonite does have some mag in it, but I don't think enough to keep the mag levels where they should be (around 1400ppm). Mag dissolves in regular tank water. I would think it would be gone almost instantly from the ca reactor, while a reactor full a media can take a year to dissolve.

The amount of co2 injected controls how fast the ca dissolves. IMO, it makes no sense to add mag to a ca reactor.

 

[cmor1701d]

I agree with CCCAPT. Mg in form of Epsom salt a/o magnesium chloride will dissolve in the water. I have no idea how you would control the amount. Dosing MG is done much less than Ca and should be about 3x the Ca level to be balanced.

 

[Jimbo7]

We are thinking about investing in one, what would be a good purchase for about 110-120 gallons water volume? Are there any specific brands that are better then others?

 

[pat8you]

I probably misunderstood him about the mg.

 

[Ziggy953]

Until you have a major demand for CA in your system adding a reactor is not that important. When you have a fully established reef with large colonies of SPS and LPS and the added frags in your frag tank then I would look into a CA reactor. Right now doing a 2 part system would take care of your CA demands. You guys have seen the pics of my tank and the large colonies I have in my tank and I have a 55g frag tank packed to the gills with SPS. I don't have a reactor on my system I just dose a 2 part system to keep my CA up. Also by doing PWCs every other week that helps keep things balanced.

Make sure you have ALK, CA and MG test kits to keep an eye on those levels. All three will play a major role in your SPS coral growth.

 

[cmor1701d]

Ziggy has way more coral than I do and doesn't need a reactor yet. I also use the 2 part but only occasionly need to dose my tank (1x/month), and that's probably because my sw mix isn't up to par for Ca and Alk.

 

[tamra&steven]

my reactor keeps up with my mg levels. that and pwc. a good brand is a korallin ca reactor, they are expensive. the one i have can work up to a 300ga tank. the more Co2 you pump into the reactor that faster you melt your media, and that means higher levels of ca, the water coming out of the reactor has a very low PH, and has to be dripped into the tank

 

[land locked]

I know cmor mentioned that Mg is dosed rarely but because I use Coral Pro salt I never have to dose Ca it is always between 425 and 450. My mag gets dosed weekly because it hangs at 1125. I do not have a lot of things (birds nest, halimedia among them) in my tank that use Ca but it is consistently perfect. I know Mg is supposed to be raised slow so that is what I am doing but it will not stay up like the Ca does, not sure why.

 

[cmor1701d]

At 1126 Mg you probably don't need to dose any. It is only slighlty lower than it should be and not low enough to be harmful. You may want to read Magnesium in Reef Aquaria for a better understanding.

You might also try contacting the salt manufacturer about the problem. They will probably ask for a sample of your salt to test and then make it up to you if it is out of spec.

 

[ccCapt]

What sg are you mixing your salt at? I've been using Red Sea Coral Pro since it came out and a fresh mix at 35ppt has consistently tested around 460 ca, 8.5 dKh and 1325 mg. What kind of mag test kit are you using?

 

[cmor1701d]

Larry, are you buying it by the bucket and mixing a small portion at a time?

I'm not getting those kind of numbers out of the bucket. I'll check my logs and post back what I've been seeing.

 

[land locked]

I mix up 55 gallons at a time but I have never tested it in the mix barrel. The test kit is Sea Chem. Although it is not easy to use, it has a reference that I check it with. I mix it to 35ppm.

 

[ccCapt]

Cmor, I buy the buckets and mix 20g at a time. I've consistently gotten those #'s when I make a fresh batch.
What kind of #'s are you getting?

Check out this unofficial salt test from RC.