WaterFall Labs

Free Chlorine

Of the total amount of chlorine, Free Chlorine is how much of it is actually doing its job. This is the number you will grade your chlorine levels on. Your Total Chlorine can be in range, but if the chlorine that is actually working is below range, then it will do you no good.

Total Chlorine

The total amount of chlorine in your pool. If your Free Chlorine amount is lower than this number, that means you have inactive chlorine.

pH

The pH level shows how acidic (lower pH) or basic (higher pH) your water is. If your pH is out of range, it can lead to skin irritation and other water-related problems depending on it being too high or too low. Algae tends to thrive when pH is high, especially if chlorine levels are low.

Alkalinity

Alkalinity helps stabilize pH levels. Without enough alkalinity, your pH is harder to control and keep in range. It is more prone to go up and down no matter how many adjustments you make with muriatic acid or soda ash.

Cyanuric Acid (Conditioner)

Cyanuric acid (better known as conditioner) protects your chlorine from the sun. Think of it like sunscreen for your chlorine. Without it, instead of lasting days, your chlorine could last only hours depending on where you live and how much sun you get. If your chlorine doesn't seem to last and you are not fighting algae or suffering some kind of leak, it is likely because there is not enough conditioner protecting your chlorine.

Calcium Hardness

Calcium Hardness helps prevent the water from leaching calcium from pool surfaces (excluding vinyl, acrylic, and fiberglass). If too low, the water becomes aggressive and pulls calcium out of the surfaces, leading to damage and scaling. Typically, resurfaces should be once every 15-20 years, but not having enough Calcium Hardness can mean a resurface in 5-10 years. They are not cheap, costing in the thousands of dollars, so you definitely would rather take care of the calcium than dealing with damaged walls. Don't have it too high either, as it will be like a wall for your chlorine, keeping it from doing its job.

Phosphates

Phosphates that appear in tests are pretty much anything algae can feed off of. This could be grass/dirt from after mowing the lawn, it could be bugs that landed in the water, it could be oils from your skin, or other less savory things (like someone peeing in the pool o_o). The more phosphates, the more food that is present for algae to eat. Having phosphates is not a red flag on its own... you can have a buffet but no customers. However, having a buffet is practically inviting algae to show up. If the number gets too high, it is a good idea to use a phosphate remover.

TDS/Salt

If you are not a salt pool, this is your Total Dissolved Solids (TDS) level. This shows you how many tiny solid particles are in the water. If there are too many, it will act as a wall, preventing your chemicals from working properly. If you are running a salt pool, this is simply your salt levels, which you will want to keep in range. Too low won't produce chlorine and too high can damage your salt cell.