I am in charge of the "water" at the hospital where I work in StoDgo.
Have the "Cisterna" cleaned by a cleaning company.Only costs 5 or 6 hundred pesos! Have your "Tinaco" cleaned as well.Buy a swimming pool Clorine and "PH" test kit.A few hundred pesos,ferreteria Americana,or any swimming pool supply store.Use those chlorine tabs,or in granulated form from the "Pool Store".Check the clorine each day or so.You need very little clorine to keep the water bactiria free.I would keep the level at 0.2 or there about.I would not drink the water,but I would wash dishes,clothes,bodies etc.!I also used this "method" to sanitize the water in the "Water Buffalos",.."Tanks"..of water in Vietnam.We drank that water.If you use too much chlorine,it can dry the skin.
Here,that treatment is really a "Pre-treatment.We pass that chlorinated water through charcoal filters,reverse osmosis treatment,and then 5 micron filters,but we drink the water! We check it for bacteria,and it is cleaner than "Bottled Water"!