Raising Calcium

[Nanz]

Im having problems raising calcium in my tank. I have a 75 gal tank with a 25 gallon sump. I am using Seachem saltmix and my Alkalinity is 2.5 and my Calcium is 330. I have tried raising it with Seachem Reef Complete but the ammount I need to add to bring up calcium to 400 is more than they recommend dosing in a day.. So I put 10ml in the tank each evening and don't notice any increas in daily testing.

Please help if you can.

[Shooter7]

Here is a link to the reef chemistry calculator. If you click on the "pick a product" part, it gives you a whole listing of various things that can be used to dose to increase calcium, along with how much to use. You can also search around in the chemistry forum for threads and articles relating to reef chemistry. It sounds as though you're going to have to figure out a Ca replacement regimen as your tank is using it up as fast as you put it in at the amounts you're using now. Here's the link:

http://home.comcast.net/~jdieck1/chem_calc3.html

[Nanz]

Im not sure I understand that calculator. When I plug in the values 100gal volume, Ca : 330 and Ca: 400 and select Seachem complete it says my balance Alk is 1.96 I thought I wanted to have Alk never go below 2.5? Im kinda lost here because no matter what I dose it does not seem to have an effect. I dont want to overdose but then again I don't hav anything in my tank but sond and live rock.

[capn_hylinur]

Here is a great article plus graphs and charts that should help:

http://web.archive.org/web/200211270...v2002/chem.htm

[Nanz]

Originally posted by capn_hylinur
Here is a great article plus graphs and charts that should help:

http://web.archive.org/web/200211270...v2002/chem.htm

I have read that article.. What I dont understand is if I want my Ca to be 400 then why does the calc say the balance Alk is 1.96 when this document says:

Alkalinity:
2.5 - 4 meq/L or 7 - 11 dKH or 125 - 200 ppm CaCO3 equivalents

Calcium:
380 - 450 ppm calcium ion or 950 - 1125 ppm CaCO3 equivalents

I know Im in Zone 3 but how can I dose that much calcium without lowering the Alk? If I dose the system with the recommended amount how much do I dose in one day?

[rhino509]

first thing first,you should test magnesium just to make sure its in range,if its not it will make getting cal and alk balanced right difficult.just my thoughts.

[Sk8r]

Ditto on the mg test: if it's 3x the proper cal reading---420 for the cal---meaning 1260 for the mg---then it will enable your alk and cal to stay up. Think of it as a three-legged stool: will collapse if any leg is missing. Mg doesn't skitter around as fast as alk and cal, but definitely needful.

[cobra2326]

Edit: please remove.

[Nanz]

Originally posted by Sk8r
Ditto on the mg test: if it's 3x the proper cal reading---420 for the cal---meaning 1260 for the mg---then it will enable your alk and cal to stay up. Think of it as a three-legged stool: will collapse if any leg is missing. Mg doesn't skitter around as fast as alk and cal, but definitely needful.

That may be the problem.. Mg is 800.. Should I try to correct Mg first or should I try to correct all 3 at the same time? Mg, Ca and Alk

[MusMusculus]

High pH will also make it hard to raise calcium and alk. Try to keep yours lights-on pH around 8.5 or so to avoid precipitation.

[Shooter7]

Do the Mg first and then see how things balance out. I started getting coral damage in my tank recently and finally did a barrage of tests and Mg came out at 990. You can use that calculator again to tell you how much and how fast of whatever you use to supplement. After you get that up to par, then test the other levels and recalculate.

[Nanz]

Originally posted by Shooter7
Do the Mg first and then see how things balance out. I started getting coral damage in my tank recently and finally did a barrage of tests and Mg came out at 990. You can use that calculator again to tell you how much and how fast of whatever you use to supplement. After you get that up to par, then test the other levels and recalculate.

Thanks everyone..

My Calcium additive does have Mg in it but it seems to be not enough. I guess I thought it would rise when Ca was added, hehe. My pH is not High in fact its low.. 7.9

[bertoni]

Ignore the balance part of the calculator. It's just wrong and misleading. I'd correct the magnesium, in 5 doses over 5 days, no more than 100 ppm per day. I'd try correcting the calcium and alkalinity, to reduce any possible stress on the animals, but that might not work. Won't hurt to try, though, if you're using calcium chloride and baking soda.

[INCEPTION7]

I could be mistaken, but a PH of 8.5 is near impossible and also impractical. Use a liquid calcium supplement to slowly raise your calcium, once it is near 400-420 then work on your alkalinity to raise it to the 8-12 DKH area. Remember, although these levels are mutually exclusive, they have a direct effect on one another. Don't shoot for the moon with calcium, I know there are success stories, but a value in the low 400's should do you fine. Also, a PH of 7.9 is fairly low but not urgent. Slowly raise the PH (.1) a day by using buffer and/or creating more surface agitation through powerheads or return pumps.

[MusMusculus]

Originally posted by INCEPTION7
I could be mistaken, but a PH of 8.5 is near impossible and also impractical. ...

pH 8.5 can be reached during lights-on hours due to removal of C02 by photosynthesis. A pH of 8.5 is about as high as you would want to see as calcium will begin to precipitate in the form of calcium carbonate, reducing both calcium and alkalinity. I did not mean to indicate that 8.5 was preferable, only that it should be the upper limit observed during photosynthetic periods.

[capn_hylinur]

I make it a habit---correct if I am wrong--to add magnesium every time I add calcium ---I use both Seachem's powders--mix it up in a milk container and add to the sump
I have never come across any documented proof that a high magnesium level is damaging and experts right on this site say that it not part of the measurement of alkalinity test kits.

[capn_hylinur]

Originally posted by INCEPTION7
I could be mistaken, but a PH of 8.5 is near impossible and also impractical. Use a liquid calcium supplement to slowly raise your calcium, once it is near 400-420 then work on your alkalinity to raise it to the 8-12 DKH area. Remember, although these levels are mutually exclusive, they have a direct effect on one another. Don't shoot for the moon with calcium, I know there are success stories, but a value in the low 400's should do you fine. Also, a PH of 7.9 is fairly low but not urgent. Slowly raise the PH (.1) a day by using buffer and/or creating more surface agitation through powerheads or return pumps.

Inception, I have been advised by our great mentors on this site not to use buffers to raise pH because they also raise the alkalinity level---rather to use calcium hydroxide (kalkwasser)

[capn_hylinur]

Originally posted by Nanz
Thanks everyone..

My Calcium additive does have Mg in it but it seems to be not enough. I guess I thought it would rise when Ca was added, hehe. My pH is not High in fact its low.. 7.9

Nanz, magnesium doesn't directly hurt coral---it is needed to help with the dissolving of calcium and bringing it up to higher levels.

It is the low calcium level that can inhibit growth of calcium

[INCEPTION7]

In my experience, I've always used buffers adding to my R/o water. Buffers, when used as directed, don't have that large of an affect on alkalinity. I run 2 calcium reactors (alkalinity reactors), add buffer to my top of water and have a reverse lighted fuge and have zero problems with PH, Alkalinty or Calcium. I think you just have to make sure you aren't reaching the top end of DKH while shooting for high calcium.

[capn_hylinur]

Originally posted by INCEPTION7
In my experience, I've always used buffers adding to my R/o water. Buffers, when used as directed, don't have that large of an affect on alkalinity. I run 2 calcium reactors (alkalinity reactors), add buffer to my top of water and have a reverse lighted fuge and have zero problems with PH, Alkalinty or Calcium. I think you just have to make sure you aren't reaching the top end of DKH while shooting for high calcium.

I was doing this with very similar equipment to yours except the calcium reactors--lucky dog I was trying to raise the pH using buffers but it was driving my pH up over the range (12-13 dKH)
so i was advised to switch to calcium hydroxide.

To avoid arguing lets agree that if you use buffers you should keep carefull watch of your alkalinity levels

[marduc]

Originally posted by capn_hylinur
I make it a habit---correct if I am wrong--to add magnesium every time I add calcium ---I use both Seachem's powders--mix it up in a milk container and add to the sump
I have never come across any documented proof that a high magnesium level is damaging and experts right on this site say that it not part of the measurement of alkalinity test kits.

Once a decent magnesium (1250 - 1350 ish) level is attained, it does not have to be attended to that frequently (I check mine monthly, it requires correction perhaps every 4 - 6 months).. elevated magnesium may or may not be a bad thing, but referring back to the three legged stool analogy that sk8r gave.. constant mag additions over time will potentially make for a lopsided stool.

There is also a potential problem of the magnesium and the calcium reacting prematurely in your container before you add it to the water, they are both very similar structurally, and both highly reactive elements.. they should be dosed separately!

And, yes as far as the buffer usage.. they can be a double edged sword.. if you just use buffers to ameliorate ph problems, without a corresponding balanced calcium addition your alk/ca/mg balancing act will get skewed all out of proportion. Make sure to test for EVERYTHING dosed into your tank prior to dosing, DO NOT let ph be an indicator that buffer needs added.

Going back to the mg situation.. I use epsom salts (MgSO4) to tweak my levels, this will add a bit of sulfate to the tank, but with the infrequency of dosing after Mg levels are where they need to be, it is minimal. If using this to adjust Mg levels, I would take it slowly and gradually raise them over a week or two.

Once Mg is in check.. then Ca and Alk can be attended to. After everything is in line.. the key to maintaining this is BALANCED additions, whether it be limewater, store bought 2-part additives, DIY 2-parts, or calcium reactor.

I highly, highly recommend anyone who has not done so to visit the reef chemistry forum and reading the numerous articles in the sticky at the top of the forum relating to this topic.

[capn_hylinur]

great post thanks--especially point number two with mixing them together--wasn't aware of that
I can't say I have read everyone of Randy's articles but I am working at it

[bertoni]

Magnesium and calcium can be mixed without problems. That's how the commercial two-part work. I would worry mostly about getting the parameters out of balance with blind dosing of a mix.

[capn_hylinur]

acutally I am having much better stability and dosing less since I have changed to water changes twice a month instead of one.