Calcium's Turn!

Hi all

Just finished getting my mag up from 1140 to 1350 with epsom salts, so the next is calcium, which currently stands at 350, it was 390 but when i added baking soda to raise the alk from 6 to 8 this is when it dropped.

So the mag is 1350 the alk was 8, tonight i tried some reef advantage calcium from seachem, need to raise it 100ppm, the calculator on this site recommends 9tsps over a period of a few days, so today i mixed a pint of ro with 2tsps of the powder, fully dissolved i added it to the tank in front of a powerhead, after a hour and half i tested calcium, still 350ppm, but my alk had dropped to 6.4.

Now i know when i add calium my alk will drop, but the calcium has not gone up, 2 things come to mind.

1-the calcium had gotten even lower then 350ppm

2-Maybe it takes longer to get a reading

Seems to me the mag is the easy part and the alk calcium is the hard, any ideas where i may be going wrong?

Thanks in advance...

 

Did you doublecheck your test results? Your tank is 55 gallons? 2 tsp should raise your calcium by about 20 I would think. I've heard some test kits might not pick up that small of a change even if they have markings/stages for all of those steps and the margin of error for testing is probably in that range anyway since that's only like a 6% change.

Personally I would doublecheck your readings and then correct your alkalinity and then add calcium again tomorrow.

I usually can see a change in levels within a half hour of dosing.

 

Also apparently that reef advantage calcium also contains strontium and magnesium. Personally I would find a straight calcium supplement if you're just trying to adjust your calcium levels. By making large adjustments with that complex supplement you could throw your strontium levels out of whack unless you're testing for that too.

If you have seachem products available to you I would use the Reef Calcium additive personally.

Seachem. Reef Advantage Calcium FAQ

 

I double checked the test results, i use a salifert calcium test, expiry date 10/11, is it not true that if i raise my alk my calcium will drop even more, alk6.4, calcium 350?

They are already very low so, whats the best way to go about this?

Cheers...

 

I've never noticed a drop in calcium when dosing alkalinity. Apparently some precipitation can happen but I don't think it's much. As long as your magnesium is where it needs to be it should prevent a drop in the calcium. I've always just dosed enough to get me where I need to go and don't ever notice it really affecting the other chemistry much.

There is no way that every time you dose one it drops the other or there would be no way to raise the levels it would just see-saw.

 

I would get your cal where you want it first then worry about the alk,
like my cal will drop from 450 to 400 I get that back up to 450 (I do it all at once but to be more conservative most people recomend no more then 20 ppm a day) then I check my alk and get that up where I want it.

IMO I would use a straight up calcium supplement like screwtape recommended.
kent turbo cal or similar.

 

i just tested my calcium today and its 365ppm, seems it takes a little longer to read ...cheers all

 

I would guess it was probably just within the margin of error of the test kit. Once your supplement is dissolved and mixed up in the tank it should test immediately higher, within a half hour probably depending on your tank's turnover rate. Good to see you saw the results expected though!