Dosing Magnesium

[mrshall1027]

We think it may be time for us to start testing/dosing magnesium. Our mixed reef tank has been running for a few months and only plan to do 10-20% water changes every other month or as needed (skimmer works great). We plan to dose our 5 gal ATO with a predetermined amount of magnesium chloride based on current test results. Anyone see a problem with this? ATO only contains RO water, nothing else, so solubility shouldn't be an issue. We run a reactor for ca and alk. Also the media claims to have Mg, but from what I read this helps give an initial boost then Mg levels drop.

Any recommendations for Mg test kit? Plan on buying the magnesium chloride from BRS,

Also anything else we should consider doing? Strontium? As mentioned above, this a mixed reef, so not interested in ULNS.

Thanks

[+etannert]

My question would be... what are you going to do if your mag spikes because the ATO is adding too much? Dilute the ATO? The reason I prefer dosing separately from ATO is it gives you more control over the amount going in from day to day - too much yesterday, add less today; too little yesterday, add more today... dosing through the ATO seems to lack that level of specificity... or am I missing something?

[+brian.srock]

I use a Red Sea Mg test kit and BRS Mg. You don't need to dose often so I would just use a gatoraid bottle with a gravity drip to dose. Once you find out what your at with whichever test kit you decide on you can use the BRS calculator to zero in your dosing. http://www.bulkreefsupply.com/reef-calculator

[victoly]

I see no issues with dosing in RO water. Eventually, you should be relying on your CaRx to provide your Mg, but as a stop gap, dosing in topoff should work fine. Several brands of CaRx media are advertised as high Mg, so if your demand is heavy you might try to mix in some of the high mg media if you want to discontinue dosing through topoff. I use the red sea magnesium kit, most of the tests available use the same method. The fit and finish of the red sea kit is very good and I haven't had any issues with it. As for trace minerals, again, since you're using a CaRx, those should be coming back into solution from the media, which is part of the genius of the design.

[Juiceman]

I use Red Sea tests for mg and I use brs mg. I just throw some in every now and again. I don't regularly dose

[FarmerTy]

+1 for the red sea Mg kit. I have been using a Calcium reactor for almost 2 years now and have had to dose Mg only once during that time to supplement. BRS has Mg and their own instructions say to dose once a month I believe so daily dosing I think is more often than needed but I don't see any problems doing it through your auto topoff either except for the aforementioned issue of specificity with the ATO method.

I believe are are products to put in with your Calcium reactor media that doses Mg as well.

[mrshall1027]

My question would be... what are you going to do if your mag spikes because the ATO is adding too much? Dilute the ATO? The reason I prefer dosing separately from ATO is it gives you more control over the amount going in from day to day - too much yesterday, add less today; too little yesterday, add more today... dosing through the ATO seems to lack that level of specificity... or am I missing something?

The ATO is pretty consistent, needs refilling every 3 days like clockwork. I plan to start low and gradually increase Mg and test at least every 3 days until i feel its consistent. Not sure if that's possible, just seeing if anyone else out there has had success with this.

[fishypets]

Before you dose anything you first need to know how much your tank is consuming? I use the Red Sea test kit.

I think you'll be surprised on how little MG your tank will consume. I dose only about 50 mls or less each month.

[Stephen]

+1 for the red sea Mg kit. I have been using a Calcium reactor for almost 2 years now and have had to dose Mg only once during that time to supplement. BRS has Mg and their own instructions say to dose once a month I believe so daily dosing I think is more often than needed but I don't see any problems doing it through your auto topoff either except for the aforementioned issue of specificity with the ATO method.

I believe are are products to put in with your Calcium reactor media that doses Mg as well.

BRS says to dose 20 oz for every gallon of calcium & alkalinity used.

[mrshall1027]

Looks like i'm ordering a red sea max kit and 1/2 gallon of BRS mag chloride and give it a go. Thanks for the input everyone.

[Stephen]

If you are doing weekly water changes and dosing calc/alk as it is why do you feel like your magnesium is low? Are your coralss not responding well to the 2 part? I haven't been dosing long on my tanks, but have seen a lot in readings that dosing trace elements is often unnecessary.

[victoly]

I don't think Mg is really a trace element. Mg is definitely readily consumed and can have a profound effect on calcium absorption and keeping some<br />Nuisance algae at bay (bryopsis specifically).

[Stephen]

So an indication of low mag might be poor growth and hair algae?

[mrshall1027]

If you are doing weekly water changes and dosing calc/alk as it is why do you feel like your magnesium is low? Are your coralss not responding well to the 2 part? I haven't been dosing long on my tanks, but have seen a lot in readings that dosing trace elements is often unnecessary.

I only plan on doing water changes every 2 or 3 months if needed. I know people who go 6 months with no issues. I'm running a skimmer, refugium, GFO, and carbon.

[FarmerTy]

I haven't done a water change in 2 years and only dosed Mg once while running my calcium reactor.

I have a ton of SPS btw.

-Ty

[mrshall1027]

I haven't done a water change in 2 years and only dosed Mg once while running my calcium reactor.

I have a ton of SPS btw.

-Ty

Which media do you buy for your calcium reactor?

2 years, that would be awesome.

[FarmerTy]

I use the Arm media, extra course that you can get from BRS.

[Bpb]

I'm considering cutting back my water change regiment myself. Lots of people mentioning the Red Sea pro test kits. I'll recommend those too. The fit an finish was mentioned. Agree. The whole setup is of excellent quality. Those glass vials are top notch. Can't tell you how many times I've dropped them on the granite countertops with no issues lol.

I've had some screwy magnesium test results the past few weeks though. I seem to be going through quite a bit. Calcium and alk are holding stable with kalkwasser use, but I'm losing about 20ppm magnesium a week. I just made a DIY dripper and dose my magnesium that way. Is 20ppm a week alot? Seems like it is considering some people only dose it a couple times a year.

[+etannert]

Shoot, I dose 10+ ml of mag per day. I keep my mag a little high (1400-1450) but considering that I have a lot of LPS and they let me know pretty fast when the mag slips, I'd rather that than the other.

[FarmerTy]

Its interesting to see everyone's dosing and maintenance regiment. They are as individual and unique as each one of our tanks are. I just wanna throw caution out there that what works on one tank may not necessarily work on another.

[offroadodge]

when I 1st started reefing I dosed MG in a bottle, to much of a PITA. I use NEOMAG from Brightwells in my CaRX now and my MG stays at around 1450-1500. Also use the extra corse ARM media as well in it.

[bimmerzs]

Looks like i'm ordering a red sea max kit and 1/2 gallon of BRS mag chloride and give it a go. Thanks for the input everyone.

A balanced magnesium regime will have magnesium chloride as well as magnesium sulfate mixed in proper porportions, BRS does mention this on their site also.

Cheers,