Now that my Ca and Mg are up...

[Sindjin]

For the past few days, I have been adjusting my Mg, Ca and ALK. My alk was high (4.6+) and it was taking a lot of CaCl to raise it.
Finally, my levels are:

Ca: 425
Mg: 1350
ALK: 4.2

From what I have been reading, I should dose equal parts of the Ca and ALK (of Randy's 2 part) but I dont want to raise my ALK anymore. So what Im planning is to monitor my Ca and make daily doses while waiting for the ALK to lower to @ 3 and THEN start dosing both Ca and ALK to maintain. Does this sound right?

 

[Weatherman]

You could stop dosing both.

As your alk drops to 3 meq/L, your calcium should drop to around 400 ppm. Both are pretty good matches to natural seawater values.

Otherwise, yes, you can continue to dose CaCl as your alk drifts down, then go back to the balanced additive approach.

 

[Randy Holmes-Farley]

I agree that you can stop both (or just the alk part if you prefer) and then start dosing both Ca and ALK in equal parts to maintain then. Focus especially on maintaining alkalinity, and calcium should follow along just fine, at least in the short term.

 

[Sindjin]

Last night, My ALK was 4.2 and Ca was 425.
This morning My Alk was 4.2 and Ca was 375.

So I dosed Ca and will recheck tonight.
In addition, my Mg is still on the low side = 1200 to 1250.
Im slowly trying to bring that up.

I think the SPS frags I have are soaking up my Ca. The one Scripps Stag is exploding...

 

[Randy Holmes-Farley]

Last night, My ALK was 4.2 and Ca was 425.
This morning My Alk was 4.2 and Ca was 375.

Unless you added a huge amount of buffer overnight, the calcium change is just noise in the testing. It cannot drop that much without a big alkalinity drop. A 50 ppm drop in calcium must be accompanied by a 2.5 meq/L (7 dKH) drop in alkalinity.

 

[Sindjin]

So, If my Alk is staying at 4.2 should I still dose the ALK portion o the recipe?

 

[Sindjin]

Randy,

First... I want to take the time to thank you for all that you do here. Since I have decided to go mainly SPS in my 120, I have been doing quite a bit of reading here in the chemistry forum. You are a wealth of knowledge! Your 2 Part recipe is a great Money saving tool and it helps me out a ton being able to make my own additives.

Second...

This morning my ALK is 4.0. My Ca read 350 then 400 then 400 when I performed 3 tests. I added a bit of CaCl to maintain that level. Is it normal for ALK to stay up so long? I am puzzled because for the past 3 days I have been dosing Ca (per the Recipe) and my Ca has not risen beyond 425 yet my ALK has remained high (4.5, now down to 4)

 

[Randy Holmes-Farley]

So, If my Alk is staying at 4.2 should I still dose the ALK portion o the recipe?

I would, unless you want the values lower. 4.2 meq/L is fine. You might dose a tad less. The amount dosed daily should really be based on alkalinity, with occasional corrections to calcium as necessary. Alkalinity is much more sensitive to over or under dosing.

I want to take the time to thank you for all that you do here.

You're quite welcome.

This morning my ALK is 4.0. My Ca read 350 then 400 then 400 when I performed 3 tests. I added a bit of CaCl to maintain that level. Is it normal for ALK to stay up so long? I am puzzled because for the past 3 days I have been dosing Ca (per the Recipe) and my Ca has not risen beyond 425 yet my ALK has remained high (4.5, now down to 4)

I'd just stick to a standard dosing regimen for a number of days and see how it is going, rather than trying to react to every number that comes along, many of which are rather noisy.