Please straighten me out

[Tautog]

I've been chasing Alkalinity using the 2- part system from BRS. I always test(Red Sea) before adding anything. After thinking I knew something, I dosed 7 floz/ day of Ca solution and 3.5 floz of Soda ash. I could never dose equal amounts based on tests. After a week, my Ca was steady at 425 ppm, my KH was 12.
What's going on here?
KH isn't getting depleted as it should, and some Acros when white from the bottom up. I'm thinking high KH.
My Mg gets depleted from weekly 40 gal WC, and I now test to adjust before change. I use Reef Crystals, mix to 1.023, after a test the Mg was 1000, Ca was 350. So I adjusted to bring levels to 1200 and 425 respectively. KH was 12.6 at mixing. Prior WC's weren't adjusted. I was always told to adjust the DT, not the WC. So, now that I hadn't dosed anything all week prior to WC, I knew everything would be low. KH was probably 7.0 or below, after WC it was 8.4. Mg at 1160, and Ca at 400. System has 200 gal. Most corals doing well, Coraline grows like a weed with a deep purple color.
What I'm I missing, my LPS owner(40 yrs) is stumped.
If I kill a coral I need to know why, and the vendor was no help either!
I went to 3 other LPS's, most said I should be happy, tank looks better than most, one asked" what's that dark purple stuff?", and yes, I can't go there anymore!
I log everything I do, so I have whatever data you need.
Please straighten me out!!!

 

[Flippers4pups]

Two part systems rarely consume equal amounts. Adjustments are almost always needed. Some systems just consume more KH than others, etc.....

With that said, adjust each value individually until it's stable with in its parameter.

When your KH is higher than 11 DKH, stop dosing alkalinity!

What dosing calculator are you using?

 

[Randy Holmes-Farley]

I use Reef Crystals, mix to 1.023, after a test the Mg was 1000, Ca was 350.

Those aren't normal numbers for Reef Crystals, and in any case, I'd boost the salinity of that salt mix rather than dose it up.

Raising the salinity to 35 ppt will boost the mg from 1000 (assuming that is real) to 1150 ppm and calcium to 401 ppm.

 

[trido]

IME Red sea Mg tests aren't always dependable in which case if your dosing Mg you might be causing an imbalance. If you have a 200G system and are doing 40G weekly WC's with only a few SPS you likely don't need to be dosing anything at all. Try testing more often, not dosing and see what your parameters balance out at.

 

[Tautog]

Two part systems rarely consume equal amounts. Adjustments are almost always needed. Some systems just consume more KH than others, etc.....

With that said, adjust each value individually until it's stable with in its parameter.

When your KH is higher than 11 DKH, stop dosing alkalinity!

What dosing calculator are you using?

I'm using BRS calculator with their 2-part stuff. I'll try dosing again this week. I'm sure my estimates on Ca are correct at 7 floz/day, but would 1.5 floz of Soda ash/day be enough to cause the reactions I seek for growth? Or even 1.0 floz/day

 

[Randy Holmes-Farley]

I'm using BRS calculator with their 2-part stuff. I'll try dosing again this week. I'm sure my estimates on Ca are correct at 7 floz/day, but would 1.5 floz of Soda ash/day be enough to cause the reactions I seek for growth? Or even 1.0 floz/day

It is much easier for folks to understand your dosing in dKH per day or ppm calcium per day. Otherwise, we have to do the math ourselves to figure out what you are doing.

It is not going to be the case that you have demand that is so imbalanced, but in the short term might need corrections before beginning equal parts, or close to equal parts dosing.

Aside from making one time corrections, my suggestion (as the person who supplied the recipe to BRS) is to dose both parts equally to maintain your desired alkalinity unless calcium is already too high (that is, above 550 ppm).

 

[Tautog]

Those aren't normal numbers for Reef Crystals, and in any case, I'd boost the salinity of that salt mix rather than dose it up.

Raising the salinity to 35 ppt will boost the mg from 1000 (assuming that is real) to 1150 ppm and calcium to 401 ppm.

I also found those #'s odd, and re-tested twice with 2 different kits.
I have always been cautious not to over do anything, be it the salt, Ca, KH, or Mg. I always measure less, especially the salt, because with the other salts, my Alkalinity would increase any way, correct?
I'll mix to a higher salinity before the WC, and dose accordingly before the change. But by increasing the salinity, and resulting in increases in Mg, Ca, and KH as well. At a salinity of 1.023, The KH was 12.6. Because I stopped dosing for the week before the WC, I'm sure my DT KH was at 7.0 or less, after the WC it was 8.4, does that sound right? So if I'm dosing, and the DT has a KH of 8.4, Ca is steady at 425, isn't my KH going to get over 13 in my DT after the WC? That's my dilemma.

 

[Randy Holmes-Farley]

If the tank has an alkalinity of 8.4 dKH and you do a 10% water change with 12 dKH water, the alkalinity only rises to 8.8 dKH.

 

[Tautog]

If the tank has an alkalinity of 8.4 dKH and you do a 10% water change with 12 dKH water, the alkalinity only rises to 8.8 dKH.

Based on a salinity of 1.023 for new water, the salinity was 12.6 dKH, the DT was at 7 dKH, and after the WC the DT was 8.4 dKH. My WC was 40 gal, 20%
I'm worried that by increasing the salinity to 1.025 my dKH would jump to 13 dKH or over, then giving my DT a higher dKH, 9 or higher which becomes a problem? Yes? Or is my testing that far off?
Or should only do the 10% WC to have a lesser effect over all in the DT?
Sorry for all the questions, and I know if I Vinegar dose these concentrations will increase by 8X. I have been using NoPox, 12ml twice a day. Would using the NoPox change concentrations as well?
Thanks again Randy, your time here with me isn't wasted, I'm learning, remembering, more, from every thread of yours I've read. It's been 40 yrs since my last Environmental Chemistry class.