This is our first experience with a cistern and keeping it free of bacteria, mold and algae is a top priority. After living in the house across the street while ours was being remodeled we found that you needed to turn on the water and then be sure to turn off the water because the municipality only turns the water on a few times each week. Of course, we found out the hard way when we left it running and it overflowed all over the side yard wasting water. So when they were working on the house they put in an automatic shut off system like you would find in the back of a toilet.
Now we asked around to find out what needed to be done to this water so that it would stay fresh. Most of what we heard was the addition of Clorox to the water but our friend Keith Daniels in Panama told us to get some copper wiring and add a few pounds of the stuff to the storage pit.
While Joe was taking down a gutter that had seen better days he found that it was hung with copper wire, he spend several hours stripping the coating and cleaning it up and then he added it to our cistern. One day last week while in San Jacinto we stopped in a small ferreteria there and asked if he had copper wire, he asked for what purpose and I told him to add to our cistern. He sells the wire by the meter (metro) of wire for .80 cents. We bought 10 meters.
Joe stripped the plastic off and we tossed these cute curlie things into the cistern.
It must be doing something because we had not needed to add Clorox to the tank in several months. You cannot drink this water even after the addition of the copper wire, it is used for bathing, laundry etc and we use 5 gal bottled water for cooking and drinking. Thanks Keith!