This is my first post here. I recently moved into a house with our first pool. I've been reading on chlorine alternatives. My motivation for this is very unusual. I have a dream of creating a completely self-sustaining home. One of the more difficult parts of such an endeavor would be rainwater storage, which would be mostly needed for growing food. I am investigating the feasibility of using a swimming pool as a rainwater storage tank. Hence, I do not necessarily require being able to swim in the pool, but just store water, and use it for growing food. There would be a second stage purification for indoor uses like drinking. Though being able to swim in the pool without chlorine, before dedicating it as rainwater storage, would be an added measure of confidence that the alternative disinfection is adequate.
I envision a pond liner covering the pool, then a removable wooden deck built over the lip of the pool, weighing down the pond liner. I think I have a rough design for such a deck that would cost like $1000 to $2000 to build. But perhaps I am naive. The pond liner and the deck would completely prevent debris, as well as make the pool into usable space. A hole can be punched in the center of the pond liner that allows rainwater to drain through the deck, and into the pool, through the hole. The gutters on the house would be rerouted to go through a sand filter or something, and then into the pool. The pool pump would be operated daily. The volume of water in the pool would vary, as water would be expended on agriculture, and we would depend on the annual rainfall to refill the pool. So the pump inlet would not be submerged all the time. So to pump the water, a hose would need to run from the pump inlet to the bottom of the deep end of the pool, and suck water from there.
I doubt plants would like being watered with chlorine, hence I ask about alternatives like copper sulfate (which would actually be good for plants in these amounts). The only downsides I have read about copper sulfate are potential staining of walls and hair. We have no blondes in the house and we swim minimally, and we would not swim at all if it were successfully converted to rainwater storage purposes. Also, I am not so concerned about purely cosmetic issues, especially since the pool walls are blue.
I have been messing around with some experiments of tap water in 4 gallon buckets in my back yard. I've tried a number of things, and here is what I have gleamed:
- Copper sulfate 500ppb has kept a bucket clear for 3 weeks. The buckets are in the shade 24/7. Still early in this experiment.
- Tap water control bucket is just starting to show the slightest signs of cloudiness after the same 3 weeks.
- Copper test strips measured about 500ppb copper at the start, then 1.5 weeks later it was down to about 200ppb, then today (3 weeks in) it measures about 400ppb. Strange that the copper decreased then increased. I tested multiple times on each occasion. Perhaps microorganisms are taking up the copper, and then liberating the copper at a later date?
- silver (1000ppb from silver citrate) by itself, and in combination with 500ppb copper, both did worse than the tap water control bucket, and got way cloudy.
- the triple combo of silver 1000ppb, copper 500ppb, and peroxide 30ppm, within a day, caused red tinted water, which I assumed was from peroxide having some reaction with the copper. And this bucket was the first to go cloudy of anything.
- previous experiments with silver citrate in concentrations as low as 10ppb, where the buckets were set in the sun, showed obviously longer time to develop algae than tap water control bucket. And none of them developed cloudiness like they did in the shade. (Evaporation in buckets that are in the sun is fast. So as you top them, you are increasing calcium and whatever else quite rapidly. That's why I thought it was better to test copper in the shade.)
So my overall question is: Is it feasible that a pool /rainwater tank can be maintained with only copper sulfate as the disinfectant? Are cosmetic reasons the only reason people don't seem to try this? I have read that copper works best if pH and calcium are kept low enough. Both of these are doable, and rainwater naturally has low ph and low calcium. In fact, I think much higher concentrations than 500ppb of copper can be soluble if pH is kept low enough.
I saw a youtube video where a guy managed his pool with copper sulfate and chlorine that was low enough to read 0. Though he did not say how sensitive his measurements were.
Okay, so here is where people smarter than I point out the flaws in my plan that are too many to number! I welcome them, and know I have a lot to learn.