Calcium dosing intervals for large adjustment

[Koresample]

I need to increase my calcium from 340 up to about 420 and i plan to do it in 3 doses. Is 12 hours enough time between doses?

I checked my PH about 6 hours after the 2nd dose (which i did 12 hrs after the first dose) and it was stable at 8.4 and none of my corals, my shrimp or Mandarin look stressed. After the first dose my calcium was at 380.

My Mg is at 1150 and my dKH is 11.

[TheRealBigAL]

I need to increase my calcium from 340 up to about 420 and i plan to do it in 3 doses. Is 12 hours enough time between doses?

I checked my PH about 6 hours after the 2nd dose (which i did 12 hrs after the first dose) and it was stable at 8.4 and none of my corals, my shrimp or Mandarin look stressed. After the first dose my calcium was at 380.

My Mg is at 1150 and my dKH is 11.


You already put a mandarin in your tank ? I thought you were going to hold off on that until your tank was more established ?

[fkshiu]

No - you should only raise Ca 20 or 30 ppm at the very most (preferably slower) within a 24 hr period. You must also raise it along with your Mg (which is currently low) or it will begin to precipitate out of solution.

Be careful of making big adjustments too quickly.

[Koresample]

he was eating frozen from the LFS and has continued to do so in my tank, plus the pods that are in it. I've been growing a ton of pods in another 10 gallon tank and re-stocking the display tank weekly, plus culturing them in my HOB refugium. He's getting pretty fat now. Each night after lights out I've been checking and my tank is crawling with pods.

[Koresample]

I've been following the dosing instructions from Randy Holmes Farley's article http://www.reefkeeping.com/issues/2006-02/rhf/index.php#2 and it talks about dosing the calcium first, then alk (which is fine), then adjusting the Mg. Is this incorrect? Does anyone else use this process?

[fkshiu]

I've been following the dosing instructions from Randy Holmes Farley's article http://www.reefkeeping.com/issues/2006-02/rhf/index.php#2 and it talks about dosing the calcium first, then alk (which is fine), then adjusting the Mg. Is this incorrect? Does anyone else use this process?

That is absolutely correct. What I meant was that you need to have all of the three key parts of the reef chemical triangle at proper levels for there to be stability.

[Koresample]

ok, so i just need to dose in small amounts over a couple more days until the Ca is correct, then do small increases in my Mg?

[lorenz0]

Go very very slow. took me 3 weeks to get my calcium up. same with Mg. no point rushing it cause nothing enjoys that

[mark]

Thought that a low Mg will limit your Ca, so what I've been doing if mixing new IO (low in Ca and Mg) is boost the Mg first then and the Ca supplement. If I ever need to adjust my system, been following the same order (Mg then Ca).

My belief is somewhat re-enforced by this article (What is that Precipitate in My Reef Aquarium? (http://www.reefkeeping.com/issues/2005-07/rhf/index.php)) or at least my understanding of it, though probably really doesn't matter what order since not running my Ca or Alk overly high.

Would also suggest raising levels over a few days. Seen this calculator (http://reef.diesyst.com/flashcalc/flashcalc.html)?

[Myka]

I dose mag, then alk, then calcium. I agree, 20-30 ppm per 24 hours.

[Koresample]

yup, that is the same (or very close) to the one i have been using here http://jdieck1.home.comcast.net/~jdieck1/chemcalc.html which i think is the same one in a different (flash) version. The funny thing is that in the calculator i used, it suggests raising the Mg, but the one you posted does not (all things being equal; Aquarium volume 35.8g, Ca now if 400, target 440, Mg now 1150, dKH 11), it says i am at my target Mg for that Ca and dKH reading.