ESV for alkalinity and kalkwasser for Calcium??

dzolot · Nov 21, 2021

Hi,

so I’ve been using kalkwasser in my 150g mixed reef for the last five years. My alk is very low at 5.2dkh. calcium is 470 and mag is 1500.

I started dosing ESV alkalinity to get the alk up. So my question - is there any reason i can’t doses ESV for alk and continue to dose kalkwasser for calcium (and to keep ph elevated)?

thank you in advance!

here’s a pic of my tank (crazy it’s doing this well with such low alk, but it is!!)

PeterC99 · Nov 21, 2021

Beautiful aquarium! Is it possible that your Alk testing is incorrect? Have you ever validated the reading with a different test kit or ICP?

dzolot · Nov 21, 2021

PeterC99 said:
Beautiful aquarium! Is it possible that your Alk testing is incorrect? Have you ever validated the reading with a different test kit or ICP?

Thank you! And good question. Yes, i tested with both Hanna and Red Sea test kit.

Garf · Nov 21, 2021

dzolot said:
Hi,

so I’ve been using kalkwasser in my 150g mixed reef for the last five years. My alk is very low at 5.2dkh. calcium is 470 and mag is 1500.

I started dosing ESV alkalinity to get the alk up. So my question - is there any reason i can’t doses ESV for alk and continue to dose kalkwasser for calcium (and to keep ph elevated)?

thank you in advance!

here’s a pic of my tank (crazy it’s doing this well with such low alk, but it is!!)

Yes, you can rebalance it slowly, then revert just to kalk, as it supplies calcium and Alkalinity.

Randy Holmes-Farley · Nov 22, 2021

dzolot said:
started dosing ESV alkalinity to get the alk up. So my question - is there any reason i can’t doses ESV for alk and continue to dose kalkwasser for calcium (and to keep ph elevated)?

You do realize that limewater (kalkwasser) supplies both calcium and alkalinity?

Reefahholic · Nov 22, 2021

ESV and Kalk both have ALK and CAL in them.

I’m not sure why you wouldn’t dose both parts of ESV.

ESV also has Mag in the Calcium component.

dzolot · Nov 22, 2021

PeterC99 said:
Beautiful aquarium! Is it possible that your Alk testing is incorrect? Have you ever validated the reading with a different test kit or ICP?

Thank you! And goof question. Yes, i tested with both Hanna and Red Sea test kit.

Randy Holmes-Farley said:
You do realize that limewater (kalkwasser) supplies both calcium and alkalinity?

yes, but over time alk diverges lower if dosing kalk only. So I’m recalibrating by using ESV alk to get my alk back up.

nereefpat · Nov 22, 2021

dzolot said:
yes, but over time alk diverges lower if dosing kalk only. So I’m recalibrating by using ESV alk to get my alk back up.

Using kalk and supplementing as needed with 1 or both parts of a 2-part like ESV is an okay plan.

Randy Holmes-Farley · Nov 22, 2021

dzolot said:
Thank you! And goof question. Yes, i tested with both Hanna and Red Sea test kit.

yes, but over time alk diverges lower if dosing kalk only. So I’m recalibrating by using ESV alk to get my alk back up.

That is true, but the effect is quite small. If you use the limewater to maintin alk (as I did), then calcium will very slowly rise. Water changes will keep that rise in check.

Here's my experience with that after dosing only limewater for 20 years:

Calcium (Ca). In my reef aquarium, I use only Instant Ocean salt and I have not added any additional calcium except as limewater for a number of years (during which time I have continued regular 1% daily water changes). So why is my calcium level (472 mg/L) higher than one would normally expect for Instant Ocean (maybe between 350 and 400 mg/L)? That long term rise in calcium is actually the expected result when using limewater to maintain alkalinity.

Limewater adds calcium and alkalinity in exactly the same proportions as in pure calcium carbonate. So if that is what is used by corals to make skeletons, and what precipitates on pumps and such, then calcium would stay constant.

But both magnesium and strontium get into growing calcium carbonate crystals in place of some of the calcium. A few percent of the calcium is replaced this way. Consequently, since the same amount of alkalinity (the carbonate) is used over time, and somewhat less than the balancing amount of calcium, calcium rises if alkalinity is maintained. I’m happy to see the result match the theory, and the calcium level seems fine to me.

dzolot · Nov 23, 2021

Randy Holmes-Farley said:
That is true, but the effect is quite small. If you use the limewater to maintin alk (as I did), then calcium will very slowly rise. Water changes will keep that rise in check.

Here's my experience with that after dosing only limewater for 20 years:

Calcium (Ca). In my reef aquarium, I use only Instant Ocean salt and I have not added any additional calcium except as limewater for a number of years (during which time I have continued regular 1% daily water changes). So why is my calcium level (472 mg/L) higher than one would normally expect for Instant Ocean (maybe between 350 and 400 mg/L)? That long term rise in calcium is actually the expected result when using limewater to maintain alkalinity.

Limewater adds calcium and alkalinity in exactly the same proportions as in pure calcium carbonate. So if that is what is used by corals to make skeletons, and what precipitates on pumps and such, then calcium would stay constant.

But both magnesium and strontium get into growing calcium carbonate crystals in place of some of the calcium. A few percent of the calcium is replaced this way. Consequently, since the same amount of alkalinity (the carbonate) is used over time, and somewhat less than the balancing amount of calcium, calcium rises if alkalinity is maintained. I’m happy to see the result match the theory, and the calcium level seems fine to me.

Thank you for that detailed response Randy!
A few things:
1) i do very infrequent water changes (about 20% every three months), so i am sure that is part of the cause of my high calc/ low alk vs what you are experiencing in your tank with daily 1% changes.
2) about three or four months ago, my calc was over 600!! I pulled back massively on the kalk dosing, so calc is more in check now, but obviously at the cost is very low alk. I don’t know what my alk was when ny calc was at 600 - just never checked alk until now!
3) how long do you recommend i take to increase alk from the 5.2 it’s at now to get it into the 7-8dkh range?

thanks again for taking the time to read and answer my post!

Tamberav · Nov 23, 2021

I think you would want to bring your alk up with the esv to the desired range (not too fast) and then resume just kalk dosing to maintain it.

Over time it may drift slowly… so then you would add a little esv alk now and again. So test alk every so often

Pntbll687 · Nov 23, 2021

You can use the esv to bring your alk back up to where you want.

Kalkwasser is best used to maintain alkalinity and calcium. It sound like you may have skipped some testing and adjust the dose to account for coral growth and alk consumption.

You could probably raise the alk over the course of a week or so. No need to rush, but no need to spread it out super far. The usual recommendation is not to exceed .5dkh raise in a single day, but I have done 1.0dkh in a day and had no issues.

Randy Holmes-Farley · Nov 23, 2021

dzolot said:
3) how long do you recommend i take to increase alk from the 5.2 it’s at now to get it into the 7-8dkh range?

maybe 5 days.

Baking soda is also a fine choice. if you run out of the ESV.

jda · Nov 23, 2021

I have never met a supplement that did not need trued up every few months. I use a CaRx which mostly adds in balance, but I have to add more carbonate a few times a year. IMO, all of this is pretty normal.