Hi Jim smith. Just a quick question. I have a larrge pond, that has alklainity of 100ppm, pH of 8.5, and is filled with bacteria. I am planning to add calcium hypochlorite into it. I understand at high pH most of the form of the hypochlorite ion will be in the less favourable form, hypochlorite, and very little hypochlorous acid will be there. Now, since hypochlorous acid is much much more effiecent (80x) at kiling bacteria, i assume once added, its concentration will be depleted quite quick. Since it is in equilibrium with hypochlorite ion and H+, so wont the equilibrium respond by shifting left, thus increasing the concentration of the hypochlorous acid and thus reducing the concentration of the hypochlorite ion?
Hi Michael, If you have any fish or aquatic life in your pond, adding calcium hypochlorite will kill them. The dead fish and plants will create an oxygen demand and may cause an anoxic condition which could create foul odors. If there is a discharge from your pond to a creek or a river, it could cause a fish kill and make you eligible for fines and other legal repercussions. As a water treatment professional, I have always treated any water discharged from my plants to ensure chlorine was never released into the environment. A body of water will always have bacteria so I am not sure what you want to accomplish. I would suggest researching hypolimnetic oxygenation systems and aeration systems instead of adding chlorine to solve your problem. As far as the chemistry of adding calcium hypochlorite to water with a pH of 8.5 and an alkalinity of 100 ppm, I would not expect the pH of the water to change if a small amount of calcium hypochlorite was added to create a low free chlorine residual. If a large amount of calcium hypochlorite was added, I would expect the pH of the water to increase since the pH of calcium hypochlorite is between 10 and 11. Consequently, I would not expect any hypoclorous acid to be formed. Jim
While In theory, you can however, if you get your tank water from a source that has already been treated, then it would be redundant to do so. On top of that, there’s most likely cheaper and safer alternatives and possible filters or filtration systems that will give you the same benefit of disinfecting rather than attempting to disinfect your tank water yourself 😃
