Got me an Alkalinity question!

[Reefer Rob]

As long a it's a constant alk depletion rather than random swings cause by a precipitation event or something else weird you're good to go. SPS tanks always seem to use more alk than ca. Randy explains this in one of his articles, but I forget the reason

[ScubaSteve]

Originally Posted by untamed

Typically, this is just normal usage of Ca/Alk. This is visible in dropping Alk due to the abundance of available Ca in general. The solution is to increase the Ca AND Alk additives to keep up with demand.

My calc remains fairly stable since I do frequent, moderate sized water changes and I've never found I've had to dose for Calc. If I get the tank to the levels I want, can I start dosing something like kalk to keep them steady or will I find that calc will build up with respect to my alk levels? I do have a bucket of Kalk that someone gave to me that I have been wanton to try but totally sure how to begin (I know the procedure, just unsure how it would affect the tank).

Originally Posted by Reefer Rob

As long a it's a constant alk depletion rather than random swings cause by a precipitation event or something else weird you're good to go. SPS tanks always seem to use more alk than ca. Randy explains this in one of his articles, but I forget the reason

Thanks Rob! I'll look for that article/quote and post it up. I have't observed any major precipitation events so it's probably just uptake causing the drop in levels. I was just baffled that the alk would drop so fast compared to the calc.

[toxic111]

its the same issue I have.. I can't keep ALK levels stable, and it is driving me crazy, I even have KALK set-up in the top-up water, but still can't keep ALK where I want it. CA & MG stay stable.

[ScubaSteve]

Originally Posted by toxic111

its the same issue I have.. I can't keep ALK levels stable, and it is driving me crazy, I even have KALK set-up in the top-up water, but still can't keep ALK where I want it. CA & MG stay stable.

Hey, let's keep in touch. Let's see if we can't figure this one out together.

[Reefer Rob]

http://reefkeeping.com/issues/2002-0...ture/index.php

From this article:

"One of the interesting features of seawater is that there is a lot more calcium than there is alkalinity. By this I mean that if all of the calcium in seawater (410 ppm; 10.25 meq/L) were to be precipitated as calcium carbonate, it would use up a total alkalinity of 20.5 meq/L. In a less drastic scenario, let's say that calcium carbonate is formed from tank water starting with an alkalinity of 3 meq/L and that it is allowed to drop to 2 meq/L. How much has the calcium declined? It is surprising for many people to learn that the calcium would only drop by 20 ppm. Consequently, many aquarists observe that their calcium levels are relatively stable, but alkalinity can vary substantially. This is exactly what one would expect based on the fact that the tank already has an abundance of calcium."

[ScubaSteve]

Ahhhhhhhhh... gotcha! Makes sense. You know, being a chemical engineer, I should have sat done and done that math myself rather than... you know... being retarded. I shall keep up the baking soda dosing.

With kalk would you imagine that I'd still need to top up alk?

Thanks Rob!

[Reefer Rob]

Kalkwasser is soooo messy! I If your going to be dosing anyway, and I don't think the balance will be perfect with kalk (or a calcium reactor), you may as well get a doser and just do 3 part (2 part)... simple