Dosing Calcium/Mag

My setup is currently depleting calcium and magnesium at a weekly rate of Mag 100ppm and Cal 50ppm. I am still dosing by hand just using a capful here and there. I also have to manually top off my sump about a gallon a day.

I am wondering if I could just add the Mag and Cal to my 5 gallon top off jug and just replenish it that way.
Will the mag and cal bind if both added to RO water?
Will these chemicals change because they are sitting in RO water for a few days before being added to the saltwater?

Thanks in advance for any help you can offer.

Edited by LakeCityReefs - March 13 2014 at 9:21am

+1 to Rich

I can see how this may seem like a good idea, but what about Alkalinity demand and then Mg demand? I'm also wondering if this partial dosing of Ca and Mg in the top off water is going to be more complicated than simple manual dosing alone.

The tests I did for you the other night revealed:
Alk 8.4 dKH
Ca 350 ppm
Mg 1200 ppm

I've been thinking... As you move the Ca up from 350 ppm, Alk is going to be dropping from it's current level of 8.4 dKH. Alk will need to be manually dosed. As the Alk and Ca increase, the need for Mg will change, especially since you are also trying to chase it up from it's current 1200 ppm.

I believe it would be a good idea to have Alk, Ca and Mg test kits on hand to watch the levels and do manual dosing as needed. Your coralline algae dominant tank should be able to keep a fairly stable level if manually dosed once or twice/week. Weekly/biweekly dosing will also allow you to cut back from ~10% weekly water changes to 10% monthly water changes.

From my visit the other night, I can tell you that the tank looks really good and coral are acting as they should. These 3 levels are not bad, just at the low end of their respective ranges.  Be careful. Chasing these numbers can lead to trouble. Go slowly and test often so you can get a feel for how the tank responds to the attempt to increase levels.

Aloha,
Mark

The Cal. and Mag. have increased easily over the past few days. I am noticing that my Alk really wont move that easy.

Good point Jackie, I have never tested before and after a water change. I do test the salinity of the water I buy from Benepets. It matches mine perfectly at 1.025 every time.

ReefdUp wrote: I usually test my new salt water and dose it before doing a water change so that it doesn't mess up my numbers.

That would be a good idea.
Is it bad to have the cal and mag that high? I don't normally keep mine that high but this salt, instant ocean reef crystals ends up really high!

bstuver wrote: ReefdUp wrote: I usually test my new salt water and dose it before doing a water change so that it doesn't mess up my numbers. That would be a good idea. Is it bad to have the cal and mag that high? I don't normally keep mine that high but this salt, instant ocean reef crystals ends up really high!

Jackie, during our ups and downs over the last two years with a copper incident wiping out half our corals, Ca reactor going down, Alk levels dropping out, messing with manual dosing, etc. my levels have been all over the board. For a period of almost six months, my Mag levels never dropped below 1460 regardless of what I did. The only noticeable result was the complete disappearance of our Bryopsis algae. As far as a Ca reading of 500, you may start to see some calcification (our calcium build up) on your pumps, power heads and the such but should be okay.

Edited by DLindquist - March 19 2014 at 3:58am

41 Posts since 2008 what the heck YOU should be ashamed Matthew? You are like the guy that sleeps on the couch in "half baked" he wakes up every once in a while says something insightful then goes back to sleep. (sorry for the highjack)

Matthew wrote: BTW, everyone, PDoug or Phillip is my LITTLE, SMALL, TINY brother. :)

You introduce me as your "not so little brother" Love you bro