1. If you drain your pool, it can "pop" out of the ground by floating on the ground water. If it pops, it must be cut up and removed. Very expensive!2. Pool water must be tested weekly in order to insure the water is safe to swim in. Pool water can spread disease. Nobody can just look at the water and know what the situation is.3. Adding chlorine tabs each week without testing the water will result in a pool that is too acidic and has too much stabilizer. If the Department of Health were testing this pool, they would close it.4. There really is no alternative to using some kind of chlorine in pools. There are other systems such as ultraviolet, ozone and ionization which can assist in pool maintenance, but only chlorine creates the necessary sanitizer residual in the pool.5. Heavy use of the pool will use up the chlorine, and the water will not have adequate sanitizer to be safe for swimmers.6. Biguanides work pretty well up north as a sanitizer. Unfortunately, they don't work well with our more extreme weather conditions. Adding chlorine to a pool with biguanides will turn it to jelly!7. Sunlight destroys chlorine. Stabilizer is added to pools to help protect the chlorine from the sun.8. Algae will form in a pool that has low chlorine, heavy use, or high levels of nitrates and phosphates. While algae is slippery, is not inherently dangerous. However, it does signify some kind of water problem.9. Consistent problems with algae usually indicate high levels of nitrates and phosphates, which promotes algae growth. Fertilizer used near the pool, chemicals used to clean pool decks, reclaimed water used to fill the pool, bird droppings on the screen cage, urine, decaying plants, and dogs are common sources of nitrates and10. You can test for nitrates and phosphates. There are commercial products which remove phosphates, but you have to drain and refill the pool if the level of nitrates is too high.