Now lets look at the contributing factors that make LSI so much fun
1-Water temp. Lets face it, your pools water temp is constantly changing, thats why you probably have a heater right? when your water temp changes so does your LSI value. The chemicals your pool needs to have your water at a perfect 0.00 LSI at 80 degrees is completly differrent then when your water temp is 70 degrees, 60 degrees, 50 degrees, 40 degrees, yes you guessed it, it needs different chemical levels even when your water reaches 32 degrees (freezing point) where it will hit in NJ. THE COLDER YOUR WATER GETS THE MORE AGREESIVE IT BECOMES, because it plumits the LSI futher and futher into the negative the colder it gets.
2-PH. pH stands for "potenz Hydrogen", or in English, the "power of Hydrogen". It is a value between 0 and 14, which determines how acidic or basic a substance is. 7.0 (in the middle) is perfectly neutral. Every whole number is 10x greater or less than the next whole number. (Example: 6.0 pH is 10x more acidic than 7.0. 5.0 pH is 100x more acidic than 7.0, because it's 10x10, so on and so forth. thanks to Alkalinity, PH is constantly on the rise... until it his it PH ceiling (henrys law)
3-Carbonate/corrected Alkalinity. Corrected Alkalinity (CA) = Total Alkalinity (TA) - (CYA x [correction factor @ pH]). Carbonate Alkalinity will determin where the PH ceiling is. Alkalinity and PH have a very close relationship, in most cases you cannot touch one without moving the other.
4-Calcium hardness. Is one of the most important factors in water chemistry, and swimming pool chemistry especially. It is one of the six LSI factors, and because it does not fluctuate much, we love using calcium hardness as a foundation for water balance, The amount of CaCO3 (ppm or mg/L) is calcium hardness, but how saturated the water is with that calcium hardness is the LSI.
5-Cyanuric Acid. (CYA) Also called conditioner or stabilizer. CYA is a chemical used to protect chlorine from direct sunlight. Direct sunlight can break down chlorine in a matter of hours. So without protection, chlorine does not last very long in outdoor pools. On the flip side the more CYA in the water the less effective the chlorine is. You'll need a higher and higher level of free available chlorine as your CYA levels go up t do the same job as when both CYA and chlorine levels were lower.
6-Total Dissolved Solids. (TDS) is a metric used in water treatment that measures all dissolved minerals, salts, chlorides, metals, organics, and many other contaminants in water. TDS impacts water conductivity and is related to corrosion, chemical efficiency, water clarity, and is an often-forgotten factor in the LSI.
PLEASE NOTE, WHEN ONE OF THESE FACTORS CHANCE, THE ENTIRE LSI CHANGES.