Originally Posted by
RichToyBox
The pH minus product will not really lower the pH until it has consumed all of the KH. The calcium hardness increaser in the spa or pool store will chemically reduce the pH without consuming the KH directly. The calcium hardness increaser is calcium chloride, providing the calcium ions that are needed to combine with the carbonate ions to make calcium carbonate, a precipitated solid that has no effect on the pH. The cause of the high pH is the migration of the calcium hydroxide by-product of the cement hydration reaction from the concrete into the pond. The calcium hydroxide has one calcium and two hydroxyl ions. The hydroxyls will combine with a hydrogen ion robbed from the bicarbonate ions, leaving behind a carbonate. But since there are two hydroxyls for each calcium and only one carbonate per calcium carbonate, the system becomes calcium starved. By adding the calcium chloride, the additional calcium is added to continue to consume the carbonate ions, (pH of over 10), and leave behind chloride ions which will combine with the sodium ions of the bicarbonate of soda, making salt.
As for the need for dechlor, you may or may not need to use it, but definitely do not need to use it until fish are added. I would use Safe, Prime, Cloram-X or similar chloramine treatment, as it will bind ammonia. During the cycle, (could be 6 weeks or more) you will find that the pond will have ammonia, and it needs to be bound. The treatments make the ammonia into ammonium, which is non-toxic, but the test kits typically measure the combined ammonia and ammonium, and does not distinguish. Look into getting the Ammonia Alert Card, which only measures the toxic ammonia, and it will let you know when and how much treatment to add.
Thanks for mentioning the ammonia alert cards — I didn’t know those existed! I just bought one. Those are nice to have around for quick checks especially when I am making changes to the Pond.
Lori
Lori WG
“If you want others to be happy, practice compassion. If you want to be happy, practice compassion.” ~ 14th Dalai Lama