Cement curing to raise pH and alkalinity?

FranklinDattein · Jul 28, 2019

Hi fellow chemistry enthusiasts,

I was wondering if anyone explored the idea of using the cement curing process to our advantage. As you know, cement curing produces calcium hydroxide and has a high pH, something between 11-13.

One idea that comes to mind, is to use small blocks of freshly made cement, to raise pH in a controlled manner.

I guess the idea is silly, because it would probably be simpler to achieve more predictable results by dosing calcium hydroxide via dosing pump, but I thought it would be worth asking.

Rlreefing · Jul 28, 2019

I am not sure that the chemistry works since the calcium is bound when it is mixed with the other substances to make cement. Additionally, I do not know about the purity of the calcium that is used for bulk cement work. You may be able to make cement rubbel to grow anaerobic bacteria.

BeejReef · Sep 18, 2019

The same thing just occurred to me, but you beat me to the "eureka" moment.
I was ignorant of the ph effect when I built my scape with liberal use of hydraulic cement, and I always had 8.4 ph the first 4 months. Down to 8.2 now.
Another thread where the OP was debating a C02 scrubber or Kalkwasser brought it to mind.

If it was safe, I'd be much more inclined to drop in four ceramic-sphere sized hunks of cement every 3-4 months for a slow release and stable ph buffer. It's just as valuable when exhausted as established and cycled live rubble rock.