Calcium?

[Supra]

Iv had several calcium requiring coral for awhile.
2 monti caps
Green slimmer
Branching monti
Acan
Frogspawn and hammer
lobo
Blasto
Candy cane
War coral
They all are growing, not super fast but growing. I was getting worried that I might be depleTing calcium. Last water change I did was a week and a half ago. So I did tests today and calcium was +520. Does this sound right? I'm using reef crystals. Thanks in advance supra

 

[ccCapt]

That's a little on the high side for what Reef Cyrstals usually mixes to (it's usually around 490), but considering the accuracy of most hobby grade test kits, that's about right.
Are you currently dosing any calcium supplement?

 

[Sniperhank]

Hm, for a 25g that is alot. I would get something started so you can either dose or have a reactor.

 

[Supra]

It's a 40 breeder, haven't updated lately. No I'm not dosing anything, I was thinking I would have to start soon, but I guess not? Wouldn't that many skeletal corals have some sort of drop in calcium?
Supra

 

[Mrc8858]

Are they frags or small still because it takes a good bit of coral growth to deplete your Ca..I have 21 corals (frags) I believe that need calcium for skeletal growth and water changes bi weekly have been enough to keep Ca up even with my alk at 4.5 meq/l

 

[Supra]

Yes they are all small, no big colonies, guess I'll just keep an eye in it and when it starts to drop ill deal with it then
Supra

 

[Sniperhank]

Yeah, you should be ok in terms of calcium and not need to dose.

 

[Jabibi]

What your alk at?? Usually when ur calciumia that high ur alk is low which is a problem

 

[uh.oh...]

whatever you decided to go with, eventually you'll be dosing something. My suggestion is that you buffer an auto top off system. Corals like stability above all else, and dosing your main tank (sump included) causes ph swings. The fastest, healthiest growth comes from very (unnaturally) stable tanks running dosing pumps or reactors. My el cheapo way is to gravity feed an auto top off that I add my buffer to

 

[Supra]

My ak was at 7, a tad low, I was gonna dose kalk in my ato. 7 isn't that bad is?
Supra

 

[Jabibi]

For sps you should be at atleast 9-11. Yea its low. Remember when your alk is down your ph will be off aswell. I would dose alk and slowly raise it to the levels you need which is 9-11

 

[ccCapt]

Natural seawater on most reefs is around 7 dKH alkalinity, so no, it's not too low. I personally keep mine around 8 dKH. Dosing kalk is not the way you want to raise your alk, if that's your goal. Use Arm&Hammer baking soda if you only want to raise alk.
Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com

 

[Jabibi]

I am not saying to dose kalk. If you dose kalk ur alkalinity will drop. I would raise ur alkalinity. Alk is what sps use to strengthen thier hard skeleton for growth and keep their color. In my sps tank my alk is at 10 and my calcium is at 440 and all my sps is doing great.

 

[Supra]

I wasn't going to dose kalk to raise levels, just to maintain. Ok now I'm really confused
Supea

 

[Jabibi]

Kalk is used to maintain calcium but will bring alk levels down. I dose kalk to keep my calcium levels steady

 

[Supra]

Hmmm I thought it maintained calcium and alk once desired levels were reached

 

[Jabibi]

Nope. The brightwell kalkwasser which is what i use is to maintain calcuim, strontium, and magnesium

 

[ccCapt]

Nope. The brightwell kalkwasser which is what i use is to maintain calcuim, strontium, and magnesium

You may be a little confused.

Kalk is used to maintain calcium and alkalinity. Adding kalk will not drop your alkalinity levels, but your magnesium and strontium levels can drop since kalk doesn't really have either of those in it and they can get used in the calcification process.
http://reefkeeping.com/issues/2005-01/rhf/index.php
Limewater is one of the most useful solutions for aquarists looking to maintain calcium and alkalinity in reef aquaria. I have used it for many years to supply my reef aquarium system. It can be inexpensive, is not too difficult to use, and can maintain the pH of reef aquaria even when it is otherwise reduced by calcium carbonate/carbon dioxide reactors or excess carbon dioxide in home air. Limewater does, however, have a number of eccentricities that aquarists need to be aware of when using it. These include high pH, limitations on how much can be added based on evaporation rates, and considerations of what else is or is not dosed along with it (such as magnesium).

Despite old beliefs that using of limewater depletes magnesium, the truth is somewhat more complicated. As was shown above, magnesium is not dosed in typical settled limewater because it is insoluble; nor is it present in very high concentration even in undissolved lime.

Using limewater can also deplete strontium, not because it is insoluble in limewater, but because there isn’t much in at least some brands of lime. Since strontium may or may not be beneficial, this may or may not be a concern.

 

[Jabibi]

The kalk i have has strontium and magnesium

 

[ccCapt]

Don't believe any marketing ploys. Science doesn't lie. Magnesium is insoluble in kalk (calcium hydroxide).
Please take the time to read and understand the article I posed above, and if you want a little more reading, here's another.
Aquarium Chemistry: Magnesium And Strontium In Limewater — Advanced Aquarist | Aquarist Magazine and Blog
The reason for this result is the well known insolubility of magnesium hydroxide. Any magnesium ions released into the solution rapidly combine with hydroxide to form insoluble magnesium hydroxide that precipitates.