[QUOTE][i]<a href=showthread.php?s=&postid=10134247#post10134247 target=_blank>Originally posted</a> by jay24k [/i]
[B]I've never heard of magnesium being calcium reactors. There is some media that some use. If I recall, I think it dolomite or something like that. I go through a ton of media and I still have to dose occasionally. Magnesium is not something you should go through that quick though. [/B][/QUOTE]

Dolomite is used in a small ratio compare to the aragonite (sp?) to help maintain the Mag level in the tank. However, dolomite dissolves at a lower ph than most media can handle. (paraphrasing Sparkss).

In addition, dolomite seems to be hard to find. *shrug*

[QUOTE][i]<a href=showthread.php?s=&postid=10134860#post10134860 target=_blank>Originally posted</a> by 250G [/i]
[B]Once SPS tanks become very mature, even small size tanks (150G), it can be almost impossible to keep up with calcium demands. A buddy of mine had a very mature 150 and he used 2 calcium reactors (equivalent of a MTC pro-cal) and ran them full blast, you could see the media disolve on a daily basis. He also dosed all his top-up water with kalc. Keeping the calcium above 400 was next to impossible b/c of the size of the SPS colonies. Kid had some masive capricornis colonies. [/B][/QUOTE]

I don't agree with that.

My 180 was 5 years old and packed, I had many corals well over a foot in diameter. I could frag a full IO bucket of corals every 6 months. Plus a ran a frag tank with about 80 frags in it at any one time. I was able to keep up with the ca demand with a reactor and a kalk reactor.

I had, what I thought was, a good reactor, But it could not keep up. I was running 120ml/min and I still couldn't keep up with the demand. I was dumping two tablespoons of Ca chloride in a day in addition to the two reactors. Got a real MTC pro-cal, and low and behold, I had no problems with my calcum demands after than.

I currently run 120ml/min at ph 6.3 and have a difficult time on my 180. I don't think it is the reactor because it is an upstream with a 8 inch diameter chamber 18" high.

I'm considering adding a second chamber. I have been using the schuran media as well and seems to do better.

Yeah add a second chamber, that should help a lot. Mine is a dual chamber reactor one is 8" diam 24" tall the other 6" 24" tall. You might need a real reactor ;) :D

I also forgot to add he had 3 - 40G SPS frag tanks plumbed to the main system.

[QUOTE][i]<a href=showthread.php?s=&postid=10135002#post10135002 target=_blank>Originally posted</a> by JB NY [/i]
[B]I don't agree with that.

My 180 was 5 years old and packed, I had many corals well over a foot in diameter. I could frag a full IO bucket of corals every 6 months. Plus a ran a frag tank with about 80 frags in it at any one time. I was able to keep up with the ca demand with a reactor and a kalk reactor.

I had, what I thought was, a good reactor, But it could not keep up. I was running 120ml/min and I still couldn't keep up with the demand. I was dumping two tablespoons of Ca chloride in a day in addition to the two reactors. Got a real MTC pro-cal, and low and behold, I had no problems with my calcum demands after than. [/B][/QUOTE]

A real reactor? Let me tell you... :) J/k.

It should be easy enough to add a second chamber right? I'm going to contact the company and see if they can create one. I would think it would just be another tube to circulate with a tube to have the effluent dump.

I am tempted to pick up a MTC. I love mine but I just don't think it can handle a tank packed with coral.

Good thread; thanks for all the contributions.
I am running a big upflow reactor and having a hard time keeping up with demand. Today, I tore it down for cleaning and reloaded it with fresh media. Added dolomite to it to see if that helps with the Mg. I wasn't having what I would call a problem with low Mg (it was testing at about 1150), but I would like to get it a little bit higher towards NSW levels. I am curious now though if I test my effluent and see what the Mg levels are. Has anyone done that on their effluent?

I got the test kits and will be putting up the numbers soon..."stay tuned to help."

Dandy7200
 

pm's you

I filled my reactor pretty full and it is supplying enough again. I guess I need to just make sure if is always at least half full.

Reef Crystal Salt
 

How does that product measure up in Mag level?

RC is about 1260 to 1290 at 1.026

Interesting read. I seem to have the opposite issue with Mag levels in my 70g sps/lps tank. It tested out today at 1680. Usually around 1425, I have never added a single thing to the tank to increase or decrease Mag, no need. I run Geo Calcium reactor on my little tank and the media never even budges in the reactor, weird huh? It has been like 2 years since I set it up. I have not gotten through my 5lb Co2 bottle in that time either. I use a Ph controller and solenoid to control the Calcium reactor. My alk is between 7-8 on any given week and my calcium is between 390-415 on any given week. I get little to no coralline algae on the tank walls. bottom, or rocks...a little but not much. It seems that things are pretty in line except that Mag level. I recently went back to old salt mix after changing to somethign new in December-May, I do a 1/3 Instant Ocean 2/3 Kent right now. It has been about a month since I went back to this salt combo and the Mag is on the rise. I use to use this combo and always kept it around 1400-1475 in the past. It seems a little high but it may not be a problem. Corals look good..one random coral showed up with some base recession this past week so I am watching things closely. It seems low Mag is more the issue. Anyone else with really high mag out there???

i use seachem reef and find that i need to dose mag from time to time..

I have been dosing magnesium aggressively to push it up and noticed that my corals were showing stress at levels above 1500 ppm. (Old test kit so levels could be higher) att those levels, I had several corals begin to bleach on their tips and then loose flesh around the bleached area. I brought the magnesium back down with two 30 gallon water changes and growth has resumed. After 4 days colors are going back to normal and most of the bare tip area is regrown.

I keep mine at 1350 and try to stay there

[QUOTE][i]<a href=showthread.php?s=&postid=10199791#post10199791 target=_blank>Originally posted</a> by Hendersonracing [/i]
[B]I keep mine at 1350 and try to stay there [/B][/QUOTE]

same here and I see my corals happy :)

Mg is consumed at a very low extent during calcification...... Coraline algae consumes Mg at a much higher rate than calcifying corals..... So if you have a lot of coraline you may have to dose Mg every now and then, but not that often. The lack of Mg won't show its bad side until it drops close to twice the amount of Ca in the water(NSW has ~3 time the amount of Mg as Ca), Mg actually keeps Ca from precipitating, by competing with Carbonate molecules..... but it will never go low enough to affect coral health, cause by then your water will have so low calcium and alkalinity you will have bigger issues worry about....

HTH.

If you haven't had the need to fill your reactor or co2 up in 2 years, then the rate of calcification in your tank is low. You either do not have a tank full of SPS or corals requiring calcium or you have little to no growth.

Well, I do have some slow growth on a lot of my frags compared to others in the neighborhood but "little to no growth"...not at all. I have a lot of frags of SPS and LPS 100+, 10 or so good size colonies that, of course grow, really nice. I'd say though, in general, my growth is slow. I am running the alk at 7-8 and calcium is right in line with that at 390-420. Ph is good, better than it use to be, 7.8-8.1. It is really weird though, the ARM media is not going down in the reactor at all. I am not sure how to speed things up, maybe I will let my alk creep up just a tad...more like 8.5 and see what goes on in the tank.