Raising Ca + Mg without Alk

EricR · Oct 12, 2022

Opinions on best way to raise calcium and magnesium without raising alkalinity (much).
Additional thoughts on maintaining trace elements without frequent water changes.
*done a bunch of reading but now just curious what more experienced people think

Considering:

Traditional 2 part (or 3 part, I guess) without the alk,,, but I guess maybe add in some trace element supplement
All for Reef — wouldn’t mind raising alk to 8-9 dKH “IF” this alone would bring Ca/Mg up to normal levels (but I doubt that’s likely)
More water changes would be an option but my nutrients are already lower than I’d like,,, already dosing phos so I could just prepare to also dose nitrates if it becomes necessary

Parameters:
1.0261 SG (Tropic Marin precision hydrometer) … was running 1.0255-ish but decided to up to 1.026-ish a month ago
77-77.5 degrees F (InkBird)
7.5 dKH (Hanna) — only falls about 0.2-0.3 dKH over two weeks between water changes
2.8 ppm NO3 (Hanna) — starting to get low slowly over the last month (from 6-8 forever)
0.03 ppm PO4 (Hanna) — finally up from 0.00 dosing NeoPhos
*LFS Milwaukee confirmed 0.00 and normally about 0.01 higher than my Hanna when detectable
Ca = 330 (LFS Red Sea)
Mg = 1200 (LFS Red Sea)
*usually 8.3 pH but I rarely ever test
…no idea if I’m actually deficient on any minor elements

Additional info if of any value:

40 gallon breeder with no sump,,, just 2 HOBs, 1 Nero 5, 2x AI Prime 16
At about 1 year since tank transfer from 37 gallon tall that was running 6-7 months
Used half live rock (from old tank) and half dry rock, plus new/dry sand …guessing dry rock/sand is where phosphate is going
6 zoas and 2 ricordea florida, no LPS or SPS
Fritz RPM (regular) salt and normal water change schedule is roughly 20-25% every other week or so

If there was an “Almost” All for Reef with everything except alk, I’d love to try something like that (if that’s even possible).
Yes, I’m trying to minimize effort on my part but realize I should just get over it and be more diligent.
I’m assuming (chemically) you can’t just mix together Ca/Mg/trace in whatever ratios you want and store/use as a single solution,,, but that’d be nice (I think).

Mark Novack · Oct 12, 2022

You can just add calcium and magnesium supplements to get the levels up but you will still need to compensate for alkalinity drop when adding those.

My method for an adjustment is 10ppm to 20ppm per day by sprinkling the powders into the sump. I use a calcium reactor to maintain it.

Randy Holmes-Farley · Oct 12, 2022

Number 1 is the best option. 2 won’t work and 3 is expensive and tedious for a large boost to calcium.

EricR · Oct 13, 2022

Thanks for the feedback.
Probably just complicating matters (for myself) by considering trace elements since I'm not even sure which (if any) I might be deficient in,,, but since Ca/Mg are low?

At any rate, easy options to just try something seem to be (for me):
- ESV B-Ionic calcium (component 2) and magnesium
- BRS calcium chloride + their "magnesium mix" dry powders
*and just get the matched alkalinity component to raise to maybe 8.5ish dKH

I see one BRS method adds Tropic Marin "C" (trace?) so not sure if I should think about that or not.

Randy Holmes-Farley · Oct 13, 2022

Balling Part C is not a suitable way to try to raise trace elements. It is not made for that purpose. It is a fine thing to add at an appropriate ratio the the alk and calcium parts of the two part.

ESV and Balling will accomplish about the same things.

EricR · Oct 19, 2022

Other than just GO SLOW and test, is there a proper order in which to bring up Ca and Mg to desired levels or just try to do both equally to see if targets are hit around the same time,,, and then adjust from there?

*only asking because I thought I read to deal with Mg first, for some reason, but now not really finding that in reading

Going with the ESV B-Ionic stuff to start when I get around to it.

Randy Holmes-Farley · Oct 19, 2022

EricR said:
Other than just GO SLOW and test, is there a proper order in which to bring up Ca and Mg to desired levels or just try to do both equally to see if targets are hit around the same time,,, and then adjust from there?

*only asking because I thought I read to deal with Mg first, for some reason, but now not really finding that in reading

Going with the ESV B-Ionic stuff to start when I get around to it.

For small changes, no. For huge changes, do magnesium first.

EricR · Oct 19, 2022

Randy Holmes-Farley said:
For small changes, no. For huge changes, do magnesium first.

Thank you.
Would +100 ppm (for both calcium and magnesium) fit into "small" or "huge" changes category ...for your response, I mean?

*with my luck, probably in the middle,,, but just wondering if I should deal with both at once or actually make an effort to target magnesium first

Randy Holmes-Farley · Oct 20, 2022

EricR said:
Thank you.
Would +100 ppm (for both calcium and magnesium) fit into "small" or "huge" changes category ...for your response, I mean?

*with my luck, probably in the middle,,, but just wondering if I should deal with both at once or actually make an effort to target magnesium first

I'd be suspicious about a 100 ppm boost to calcium actually being needed, but magnesium first is never wrong.