Magnesium testing

[Saltysteve]

Interested in the numbers.........
Please do not vote if you are guessing.

[Ruth]

I test for magnesium at least once a month and dose as required. I have found it has made a difference in keeping calcium and alk in balance - also notice that I have more coraline growth which isn't always a good thing when it is on the glass/acrylic.

Edit: I also run magnesium chips in my calcium reactors so do not have to dose near as often as I did before.

[surgeonfish]

I do not test for calcium. I was told that if you get a white ring around your tank and/or sump at the water level your magnesium level is low. Has anyone noticed this? For those who test regulary do you find you also have to add Mg regularly? If so what kind of supplement are you using?
Tanks

[Quagmire]

I started to dose when I couldn't get my ca up.I had to dose weekly with water changes.Since Ive started useing a salt with higher mg,I dont think I'll have to dose as much,but I'll have to dose more ca as its lower in that.

The only white ring Ive ever gotten was salt creep

[Johnny Reefer]

I have been testing for Mg, and dosing....up to now....but I'm just now going to stop. It has been conveyed to me that it is not necessary because I do not keep any SPS. Just LPS, softies and I have 1 clam, plus a handful of other inverts. I will continue to test for Ca and maintain that at ~325, but for Mg I have to answer...."No. I don't bother".

Cheers,

[BMW Rider]

I test MG, CA and alk regularly. I find I need to periodically dose a bit of MG to maintain the levels. The CA and alk usually stay where I want them within acceptable limits.

[Aquattro]

Originally Posted by Johnny Reefer

... it is not necessary because I do not keep any SPS. Just LPS, softies and I have 1 clam, .

All of the above critters need Ca just like SPS, so this would be a bad reason to allow Ca to drop below ~350. Clams and LPS especially need Ca, just as much as SPS.

And while I don't test or need Mg, if you have to in order to keep levels right for your critters, then by all means you should do it. IMHO

[Johnny Reefer]

Originally Posted by reef_raf

All of the above critters need Ca just like SPS, ......

Yes, I know they do.

Originally Posted by reef_raf

.... so this would be a bad reason to allow Ca to drop below ~350. Clams and LPS especially need Ca, just as much as SPS.

Well, now I'm getting conflicting advice.
Hard to know what to go with.

Edit: I got clarification on the ~325 ppm Ca thing. Disregard. ~350 it is. Thanx Brad.

[Jaws]

I started dosing Mg after finding out mine was only at 1200 and natural sea water is well above that. I've never had that great coralline growth plus I've had poor coral growth as well as poor polyp extension. I haven't noticed a difference in coralline growth but my polyp extension has improved quite a bit probably also to do with the additional flow I added. I've also noticed a bit of an increase in growth and I'm still working on increasing it to the level it should be. I'm not sure how important Mg is for LPS and softies but because SPS are so finicky, I would definitely recommend dosing anything within reason that will mimic their natural habitat.

[reeferaddict]

Originally Posted by Johnny Reefer

Yes, I know they do.

Well, now I'm getting conflicting advice.
Hard to know what to go with.

Edit: I got clarification on the ~325 ppm Ca thing. Disregard. ~350 it is. Thanx Brad.

Hey Mark...

I don't understand what the conflicting advice is here....

ANYTHING that has a calcium carbonate skeleton or shell NEEDS Calcium and Magnesium... and more importantly... Carbonates... Alkalinity is consumed at a much higher rate than anything than anything else. Having said that, natural sea water values are what we have to shoot for for all these levels.... Mag is acceptable at 1250 - 1400 ppm... Cacium anywhere between 380 and 480... and Alk at 8 - 11 dKH... LPS may not demand as much as SPS... but they are still STONY corals... same with clams... Magnesium is used at a much slower rate than Calcium... but is important to keep the Calcium and Carbonate BIO available... I keep my Mag at around 1300 and only have to test monthly and dose every two weeks... all my make up water is run through my Kalkreactor... and using Kalk actually depletes the Magnesium... some people that use Calcium Reactors report not having to dose Mag at all, as is also the case with people with low calcification demands that do regular water changes. I've never read anything to the contrary of what I have just explained, but if anyone wants to butt in and correct me... please do.