epsom salts

[timrandlerv10]

so we've been battling Mg problems for months now...either everybody's magnesium test kit is wrong, our something is eating magnesium out of the water.

to make matters worse, when the mag gets out of balance, calcium goes too...then usually alk and ph are harder to keep stable as well (not sure why those two are impacted though).

we're going through about large bottle of magnesium supplement every two weeks...which is getting expensive--not to mention we are still on the low end of 1200.

i've read some about using epsom salts, but i have a bunch of weird questions:

1) is one brand better than another?
2) does the sulphur build up, and if so, how does one keep it in check?
3) does a 100ppm per day limit seem adequate for changes, or do we need to be lower than that?
4) can the epsom salts be mixed in ro/di water, and then added as top off water?


i know there is an alternative like this for calcium and alk supplements...where do i go to start learning about those?

thanks,
tim

 

[8BALL_99]

I've used a few different brands they all seem about the same to me

Yes Sulphur does build up. Its not really a great Idea to just use magnesium sulfate to raise MG.. Your much better off using the 2 part recipe.. 3 cups Magnesium sulfate, 5 cups magnesium chloride. I've got some Magnesium Chloride if your interested. I'm out of MG Sulfate though. But you can buy epsom salt in pretty big bags at sams or costco.

Yes if you follow the 2 part instructions you mix 5 cups of MG Chloride with 3 cups MG sulfate with 1 gallon of RO water. Here is a calculator for dosing 2 part http://www.2partcalculator.com/.. HTH

Will

 

[0p3n Brain]

Take a look in the Reef Chemistry forum and search for magnesium. There's a couple of good threads and some articles that I found very interesting.

I used Epsom Salt for a while and didn't really notice a difference good or bad. I too was concerned about the sulphate buildup but never really determined if it caused a problem.

Bottom line - I quit using the epsom salt, quit testing for magnesium and just do more frequent water changes.

 

[8BALL_99]

<a href=showthread.php?s=&postid=12421726#post12421726 target=_blank>Originally posted</a> by 0p3n Brain
Take a look in the Reef Chemistry forum and search for magnesium. There's a couple of good threads and some articles that I found very interesting.

I used Epsom Salt for a while and didn't really notice a difference good or bad. I too was concerned about the sulphate buildup but never really determined if it caused a problem.

Bottom line - I quit using the epsom salt, quit testing for magnesium and just do more frequent water changes.

EEK you should still test from time to time.. ALK, CA and MG wont be kept in check with just water changes in a reef tank. They might stay well enough for things to live.. But your levels will probably be lower then they should. I'm amazed at how much crap my tank seems to go through.

 

[timrandlerv10]

...why do you use

3 cups Magnesium sulfate, 5 cups magnesium chloride

?

if mg sulfate is bad, and mg chloride is better, why not just use magnesium chloride?

 

[8BALL_99]

MG sulfate isn't really bad. But trying to raise your MG levels with just MG sulfate isn't a great idea. As youve already noticed it takes a lot to raise the MG level. The idea is you want a balance. If you do enough water changes the sulfate shouldn't really be a Problem, But they also say it messes with the Ions in the water and can cause other issues. If you really want to know all the details do a search over in the chemistry forum or even Google it.. Some of it is interesting most of it puts me to sleep after 3 pages though. All of them say the same thing.. Your better off using both MG sulfate and MG chloride together to keep your water balanced.

Here is a good article on MG and 2 Part. http://reefkeeping.com/issues/2006-07/rhf/index.php Its not but a couple pages long

Will

 

[0p3n Brain]

<a href=showthread.php?s=&postid=12421778#post12421778 target=_blank>Originally posted</a> by 8BALL_99
EEK you should still test from time to time.. ALK, CA and MG wont be kept in check with just water changes in a reef tank. They might stay well enough for things to live.. But your levels will probably be lower then they should. I'm amazed at how much crap my tank seems to go through.

I didn't say I don't check Alk and Ca. I do that regularly and they are always in check. I just quit checking magnesium. My tank has been fine.

 

[8BALL_99]

You can have low MG levels and have NP at all. If they get really low then you start having trouble with Alk.. Then the Alk causes problems with CA ect ect.. I'm sure you know all that.. Low MG just slows coral growth. Stuff will still live even grow.. Just things grow slower.. SPS grow ALOT slower. If you do alot of water changes and dont dose Kalk you might be fine.. But I'd still test from time to time. MG is cheap and the test isn't hard. If you test Alk Ca and PH, why not MG?

Will

 

[teamreefers]

What brand of salt are you using? We've been having problems with Mg and Ca.
Kept dosing and dosing and just couldn't raise it. Come to find out Reef Crystals had some bad mix earlier this year and our salt was deficient.

Just received our 2 part order and going to start doing that.

Jack

 

[Tomoko Schum]

This short article by Dr. Randy Holmes-Farley explains the relationship of calcium, alkalinity and magnesium very nicely. It explains clearly what's happening in your tank.

Coralline algae is a big consumer of magnesium. When my Mg is at a good level (1300 ppm or so), coralline algae grows really well (too well). I can tell when it falls below that level because I don't have to scrape coralline algae off the glass surface as much then.

It takes a lot of magnesium supplement to bring the level up from 1200 to 1300. I don't remember how much a bottle of Kent Mg supplement can raise mg level per dose, but it quickly becomes very expensive to keep the level up with Kent's stuff. If you have a large tank, I suggest you go with Randy's DIY magnesium formula.

Tomoko

 

[Siffy]

I wouldn't let the how of raising Mg to worry you too much. If all you have available is MgCl, use it. If all you have available is MgSO4, use that. There's plenty of tanks that look great and have healthy corals that use either one or the other or both (in either a balanced mix or not).

Will,
You may want to read that article you linked. Randy has written 2 articles on recipes for two-part/magnesium and his "ionically balanced" formula changed for Mg. The 5:3 ratio you mentioned was replaced. I can't remember why, but here's the new one.

http://reefkeeping.com/issues/2006-07/rhf/index.php#15
"3. Using both Epsom salts and MAG flake, dissolve 7¼ cups MAG flake and ¾ cup Epsom salts in one gallon of water, and use that to supplement magnesium in amounts determined using this linked online calculator, with the entry "Randy's Recipes 1 and 2 Versions A and B," and ignore for this purpose what those designations mean. This recipe is preferred, but its advantage over recipe #2 is minimal in most cases."

As a side note, this is what I use, but I typically find that not all of the salts dissolve unless the water is heated or at least warm. Some even suggest boiling first. In any case, the highest concentration you'll be able to make is around 50,000ppm, I believe, and you can use that number to calculate (weighted average) how much to add or to double check any of the online 2-part calculators.

 

[8BALL_99]

Lol your right. Thanks!, I didn't even knotice they had changed it.. I wonder why. Thats easier for me anyway since I have plenty of MG chloride and I'm out of Epsom now I dont have to order more!

When I mix my 2 part up I put RO water in a 2 gallon bucket with a powerhead.. I then add whatever I'm making.. Be it baking soda or epsom, ect. I then just let it run for about 15 mins or so with the lid on the bucket. It mixes it pretty well after this it pretty much stays mixed. I then put it in 1 gallon jugs and just give them a quick shake before I dose..

Will

 

[Siffy]

I don't know why he never mentions that it's different in either article, but that makes it really hard to catch. IMO, he should put a link to the new article in the old one and mention in the 2nd one that it's different from the old one.

The powerhead has got to be the easiest way if you're mixing enough, but since I only make about a half gallon at a time it's easy enough to shake pretty well and less pouring. I dose a lot of kalk so it takes a while to use up the 2 part. Letting it mix itself is probably the most thorough, but I've been happy with only a thin layer on the bottom of both my CaCL and NaCO3 jugs. It's just my Mg mix that often has a 1/2" thick layer of undissolved solids on the bottom. I don't worry about it much as I'm pretty faithful about testing.

 

[8BALL_99]

I would have never knoticed it.. I mix up the stuff so much I dont even read the how to's for two part instructions anymore. Inless it said something like Recipe 3 I would have just skipped over it haha.

Well I have two really Great Kalk stirrers that I just run water in lol. My Ph stays on the high side so anytime I fill them up My ATO pretty much doesnt run cause the Ph is higher then my set point. :| BTW you might need to keep an extra eye on your MG.. I've read in a few different places that Kalk can lower MG levels.. Even when I was able to run Kalk I never really knoticed much of a difference though..

Will

 

[Tomoko Schum]

Beaslbob's comments

Beaslbob's comments

Beaslbob wants me to post this message here for him.

-----------------------------------------------------------------------------------
If timrandlerv10 wants I have both magnesium chloride and magnesium sulfate (Epsom Salts). Just contact me if they need some.

One of the really eye opening things about the diy two part, is the amount of magnesium dosing that can be required. My 55g was down to 800-900ppm and required 3-4 pounds (yes pounds!!!!!!) of epsom salts to get back up to 1350ppm.

I agree with 8ball that water changes will not maintain magnesium. Or anything else for that matter. What happens is that say you are changing 10% of the water. The tank will build up to 10 times the change between water changes. 20% then 5 times. So if you are changing 1/x of the water, the tank builds up to x times the change between water changes. After the water change the tank is (x-1) times the change between water changes. Then just befor ethe next water changes the tank is back up to x times.

For instance say you are increasing nitrates at 1 per day and change 10% each week. The tank builds up to (1/day x7days=7)x10=70ppm nitrates. If you started with calcium a 400ppm and lost 1ppm/day, the tank would be 400-70=330ppm just before the water change. Then up to 337 after the water change and back down to 330 just before the next. With nitrates it would be 70 down to 63 back up to 70.

So in order to control nitrates you have to consume them as they are being generated. So nitrates are always 0 (or less than 5). With calcium (and alk and magnesium) you have to buffer or replace them as they are being consumed. So that calcium is always 400ppm regardless of the water changes.

Woopsies too long. sorry. LOL

Anyway, he or any one else, has a mag measurement and tank size, I will measure out what he needs for a one time "fix" and give him some more to continue.

my .02

Bob Beasley

 

[Tomoko Schum]

I don't know why he never mentions that it's different in either article

Actually he does in the article to which 8ball posted the link. Here's what Dr. Randy wrote:

"Note also that this recipe (#3) is different from that given in my DIY two-part recipe, because in that case more magnesium sulfate is necessary to offset the rise in chloride that is provided by both the calcium chloride and the magnesium chloride."

I've read in a few different places that Kalk can lower MG levels.. Even when I was able to run Kalk I never really knoticed much of a difference though..

Here's what Dr. Randy wrote about kalk causing Mg to drop:

"A potential sink that has been described by some hobbyists is the precipitation of magnesium by limewater (kalkwasser). Both magnesium hydroxide and magnesium carbonate have been suggested. I do not believe that either is an important process in most aquaria. Adding any high pH additive, including limewater, results in the transient formation of magnesium hydroxide. This material quickly redissolves on mixing such that the local pH drops below about 8.6.-9.0. Magnesium carbonate is a more complicated issue, as it is near its solubility limit in seawater and may quickly get coated with a less soluble magnesium calcite. These issues have been dealt with by Bingman20 in much greater detail, and his conclusion is that neither of these precipitates is a likely sink for magnesium."

Tomoko

 

[timrandlerv10]

Tomoko,

We're at 1100mg/300ca for 50 gallons, 1100mg/300ca for 120 gallons, and 1000mg/280ca for 10. Alk is 8 across the board. pH is dropping, now hitting 7.7-7.8 in the mornings, and 7.8 solid in the afternoons.

We got epsom salts today...i tried to find nigari, but it doesnt seem that anybody local has it. Since we've been going through the supplements pretty heavily the last month, I think I'll be examining the DIY two-part very soon!

on a good note, i noticed today that my frogspawn has almost 10 new heads on it. It had two big ones...then we realized there were really FOUR on there, and when I went to show Adam how great it was that we had four, i saw six more all along the outside edges. No wonder we dont have any calcium or magnesium!

would you mind giving Bob my email, timrandlerv10@yahoo.com please?

thanks,
tim

oh...if anybody wants to chime in on using/mixing/ruining 2 part feel free to start teaching!

 

[8BALL_99]

Kewl so Kalk shouldn't effect your Mg.. I had read a few places that it did.. But like I said I never knoticed a difference in how much Mg I was adding with or without Kalk so I kinda figured it didn't matter much. I've never been able to add alot of kalk though due to High PH

 

[Siffy]

<a href=showthread.php?s=&postid=12430097#post12430097 target=_blank>Originally posted</a> by 8BALL_99
I would have never knoticed it.. I mix up the stuff so much I dont even read the how to's for two part instructions anymore. Inless it said something like Recipe 3 I would have just skipped over it haha.

And I never noticed the exact thing I was complaining about. Thanks Tomoko. I really can't remember if I ever saw that or not. And I pasted from the same article. I tend to skip over a lot of what Randy says.

<a href=showthread.php?s=&postid=12430097#post12430097 target=_blank>Originally posted</a> by 8BALL_99
Well I have two really Great Kalk stirrers that I just run water in lol. My Ph stays on the high side so anytime I fill them up My ATO pretty much doesnt run cause the Ph is higher then my set point. :| BTW you might need to keep an extra eye on your MG.. I've read in a few different places that Kalk can lower MG levels.. Even when I was able to run Kalk I never really knoticed much of a difference though..

Will

Same with my pH, partially from tons of fresh air around the tank and added to that by kalk. I have been watching my Mg lately. Last week I just bumped it way up attempting to nuke some bryopsis with elevated sulfate levels. Well, didn't work and it's still doing fine in a glad bowl until one of the guys that read the ID thread comes to pick it up this week. He actually collects macros. I just ran a fairly full range of tests and my Mg has come down just a little since the last time I added any. I boosted it up from 1450ppm to between 1750 and 1800ppm and left it there for a few days to see if it had any effect on the pest algae. After it still looked fine I brought everything down with RO/DI dilution since my sg was running a couple points high anyway. 2 gallons of dilution on my 40g of water should have brought Mg down to 1680ppm by my math (with a 1770 starting point) and I just tested it at 1650ppm. I really need to do some big water changes to get it back down asap and new salt should be here tomorrow (well, today now technically). After my last water change I decided to give up on a brand after the newly mixed water was Alk 6+meq/L, Ca 320ppm, Mg <1150ppm @ 1.025sg. I can work with things being low, but Alk numbers that high I just can't deal with. Luckily the tank's alk was already low at the time, but that's not always the case.

Like I said, just tested for everything pretty much, so I might as well:
Temp 79.somethingF
sg 1.026
Alk 3.95meq/L
pH 8.38 (lights go out about sunset, and this is with no kalk since first thing this morning when I mixed up new and I always let it settle for 24 hours sealed before using)
Ca 450ppm
Mg 1650ppm
NO3 Undetectable
PO4 Undetectable