WHAT IS BALANCED WATER?
WHY IS MY POOL GREEN?!!?
Water is known as the universal solvent. It seeks to dissolve everything that it comes into contact with. That includes your pool's surface, pump, filter, heater, plumbing, you name it. Balanced water is water that is chemically maintained within very strict tolerances to reduce its impact on your pool components.
Pool water can be in one of three states; scaling, aggressive/corrosive, or equilibrium. Corrosive/aggressive water can etch pool surfaces, corrode heater coils and cause premature wear on the pump/filter systems. Scaling water can deposit minerals (calcium) on tiles, surfaces and inside plumbing lines and pumps. Balanced water has reached equilibrium. It's mineral saturation has been satisfied so it doesn't pull them from your pool walls, which adds years to your pool finish. Moreover, it does not drop minerals out of solution where it forms calcium scales on tiles and aggregate. The pH is steady so it does not allow intermittent or long term corrosiveness, thereby preventing premature wear on finishes and pump/filter components.
We measure water balance using the Langelier Saturation Index (LSI). Created in 1936 by Professor Wilfred Langelier, the index was developed to determine how to lay down a slight calcium deposit inside municipal pipes to help protect them from corrosion. It measures the corrosive potential of water by plotting the measurement of pH, alkalinity, and calcium hardness. To complete the calculation, temperature and stabilizer are also factored into the equation, although their impact is less.
After measuring all these dynamics of your pool water, we make adjustments to maintain your water as close to center as possible. Our goal: water that has reached equilibrium. There could be several reasons for this condition. The most obvious is poor circulation. Even water that contains adequate chlorine can form algae or turn cloudy if there's no circulation. If you're pump is running 6-8 hours per day, and your filter is relatively clean and no obstruction in flow exists, circulation is probably fine.
It could also be that the level of phosphates in your water is extremely high. Phosphate is algae food. The more there is, the more food algae has to grow on. Make sure your pool service measures phosphates and kills it. Many pool services rely solely on shocking with chlorine to remove algae. Shocking does that, but it does NOT remove phosphate. In fact, when algae are killed they release phosphates back into the water where it fuels subsequent algae blooms. After shocking, phosphate killer should be used to remove the algea-growing food released after algae have been killed.
Normally, when chlorine levels are maintained and water still turns green, it's the stabilizer level that's to blame. Stabilizer (cyanuric acid) is added to pools to keep UV rays from burning off chlorine. It binds with chlorine and protects it from the UV rays. Excess amounts have a negative effect, rendering the chlorine powerless. If this is the case, you may find that it takes many times the normal amount of chlorine to keep algae at bay.
Stabilizer levels should be maintained at 30-50 PPM. If you've maintained your pool on a strict diet of chlorine tablets, there's a good chance your stabilizer level has risen to 100 PPM or even higher. Tablets are stabilized and their constant use causes an excess build up. When that happens, you'll need much more chlorine than normall to keep your pool sanitized. There is no way to reduce stabilizer levels except by draining pool water.
Alkalinity is the water's ability to withstand changes in pH. Additions of chlorine can cause swings in pH, as can rain water, acid additions and other chemical additions. When the alkalinity is within a very specific range, the water has the ability to buffer these pH changes, thereby allowing a more steady-state pH.
From a water chemistry standpoint, your pool service should analyze the pH, chlorine, and alkalinity each week. Every two to three weeks they should analyze for stabilizer levels and calcium. Every four to six weeks they should check for phosphate buildup. Every three to 6 months they should analyze for metal buildup.
From a systems standpoint, your service should check the operation of your filter and pump each week. As well, they should inspect for water or air leaks in plumbing lines. At least monthly, your filter should be cleaned and inspected (cartridge). If you have a sand filter, it should be backwashed every 4-6 weeks. If you have a DE filter, it should be backwashed and re-charged with DE every month.