Kalkwasser dosing: Alk dropping, Calcium and Magnesium holding.

[RockStacker]

First, a little history:

For a few months I was manually dosing the BRS 2-part solution and the parameters were doing fine during that time.
Ca: 440-450ppm.
Mg: 1440-1450ppm
Alk: 7.0dkh.

The Alk was a little lower than what I would like (I would prefer 8.0) but since I got the manual dosing amounts and schedule down, I did not want to mess with it any more.

However, manual dosing gets old after a few months :)

So I switched gears and started using Kalkwasser, dosed via Aqualifter pump connected to my ReefKeeper Lite. It doses for 1 minute every 30 minutes, 24/7.
I am still gradually increasing the Kalkwasser saturation to get it just right and not over/under dose.


Now a few weeks into this routine, I noticed that the Alkalinity is dropping considerably while Calcium and Magnesium holds steady.
Ca: 385-390ppm
Mg: 1440-1450ppm.

I have to manually dose the Alk part of the BRS 2-part solution to get back up.
If I do not manually dose Alk, it would drop from 8.0dKH to 7.0dKH within a week. It even went as low as 6.4dKH before I intervened once.

Also, the annoying part is I can't just dump enough Alk at one time to spike it to 8.0dKH, I have to do it gradually but it has been a moving target since it seems to be constantly depleted faster than the Kalkwasser can replenish.

So my questions are:
1. Isn't Kalkwasser (at proper saturation) supposed to proportionally increase Ca and Alk?
2. What's wrong with my case? Why is Calcium OK and Alk dropping? Do I need to increase the saturation?
3. What else could consume carbonates at a higher rate than calcium?

If I have to manually dose Alk on top of the Kalkwasser, then I am thinking of just going back to manually dosing the 2-part again since I have to manually dose something anyway.
But it is just so much nicer to have a kalk doser since the dosing is more regulated and I can leave it unattended.

 

[chichimom79]

I would try to increase your kalk saturation. How much kalk are you using per gallon?

 

[RockStacker]

Right now I am mixing 4 teaspoons kalkwasser powder per 5 gallon container. This is roughly 40% of saturation.
The Aqualifter pump is hooked up to this 5 gallon container and I make a new batch of Kalkwasser solution when needed (every 3 or 4 days).

I will increase it to 6 teaspoons per 5 gallon container and see how that goes in the next few days. That would make it roughly 60% saturation.
This is assuming that 100% saturation is 2 teaspoons per gallon of RO/DI water.

Calcium and Mag are getting close to the high side already, so I do not want to overshoot it.

BTW: pH is at 8.0.

 

[noy]

kalk is calcium hydroxide - it increases calcium directly but you need dissolved co2 to react with the hydroxide to form bicarbonate to raise alk.

Don't think you want to increase saturation as this will add more hydroxide w/o the co2 having a chance to replenish

stop dosing kalk for now and add alk (per part2) to get your alk back up.

 

[salt_for_brains]

I'm sorry I can't help much with your issue but there is some info out there of people having the same issue as you. It is supposed to equally maintain but some systems deplete levels faster than others.

On a side note------use picking lime it is much cheaper at $2 a pound in my area. Go to Walmart and pick up Mrs. Wages pickling lime it is identical to Kalk (Calcium Hydroxide)

 

[Civicdemon]

you can does soda ash to bring up your ALK..

 

[RockStacker]

kalk is calcium hydroxide - it increases calcium directly but you need dissolved co2 to react with the hydroxide to form bicarbonate to raise alk.

Don't think you want to increase saturation as this will add more hydroxide w/o the co2 having a chance to replenish

stop dosing kalk for now and add alk (per part2) to get your alk back up.

I wonder if the addition of macroalgae in the display tank further compounded the Alk deficiency.
The macroalgae would take in CO2 during the day and could be limiting the necessary chemical reaction.
I will have to see if I can test CO2 levels in my tank.

 

[RockStacker]

On a side note------use picking lime it is much cheaper at $2 a pound in my area. Go to Walmart and pick up Mrs. Wages pickling lime it is identical to Kalk (Calcium Hydroxide)

Thanks.
That product is seasonal over here so I got the BRS one since I was ordering other stuff anyway. Same case with canning jars - which annoys me because I try to make fruit jams year round.
The 4.5 pound jar at BRS was around $12.00, so it was just a little bit more expensive at around $2.66 a pound.
I am checking for it whenever I am at local stores - I think they have a very long shelf life so I can keep a pack in reserve until I run out of the BRS one (which could take months).

 

[fastrd400]

I use the BRS 2 part. However, I add the alk to my ATO container. Dosing that way, my alk stays between 8.4 and 9.0. I also have a pair of doses that I have as yet to hook up. The RO and alk has worked really well for quite some time now.

 

[RockStacker]

I use the BRS 2 part. However, I add the alk to my ATO container. Dosing that way, my alk stays between 8.4 and 9.0. I also have a pair of doses that I have as yet to hook up. The RO and alk has worked really well for quite some time now.

If it comes to that, I could go back to the 2-part and set up two 5 gallon dosing containers. One for the calcium, and the other for the alk. They would dose at different times or at different parts of the tank.
But I am really trying to see if I can make this work with just a single kalk doser.

 

[fastrd400]

I dose calcium once a week, whenever I refill my RO container and that's it.