* Special test only ran if needed

the inside of your filtration equipment and accessories.  We recommend bringing in a sample of water (at least a quart) at least one time per month for a check up to stay out of trouble.  Small adjustments as needed are so much easier than procrastinating until major repairs are needed.  Prevent yourself from needing costly repair costs and headaches and grab that sample today!  We recommend 12"-18" below the surface for the sample.  Here are the things we look at:

Water balance and sanitizer levels are key to keeping your pool and/or spa clear and healthy.  Poor water balance does a lot of damage at a microscopic level to the pool surface and equipment each day.  As days, weeks, and months go by unchecked the water can literally destroy finish of your pool or eat out the

If LSI Index is between -0.3 and +0.3 pool water is Balanced.
When pool water is balanced, it has no effect on the pool or equipment. There are two values you can readily change to help improve your LSI value to get it into the optimum range: pH and Alkalinity level.

If LSI Index is less than -0.3 pool water is Corrosive.
Pool water may cause etching, pitting, dissolving and staining of walls, grouting and plumbing.

As Stabilizer Increases, LSI Decreases
As Total Dissolved Solids Increase, LSI Decreases

To raise your LSI value, add sodium bicarbonate or baking soda (can be found in pool supply stores). Consult the calculator above to determine the target Alkalinity value (recommended range is 80-120ppm; however, you may find that a level lower than 80 may be ideal for a balanced LSI value).

If LSI Index is greater than +0.3 pool water is Scale Forming.
Pool water may deposit excess minerals on the pool and equipment. Scale generally appears as white or lightly colored rough blotches on the pool walls. It also adheres to other objects in the pool, piping and filter system. Scale can restrict water flow, shortening filter runs and reducing filtration efficiency.

As Temperature Increases LSI Increases
As Total Alkalinity Increases LSI Increases
As pH Increases, LSI Increases
As Calcium Hardness Increases, LSI Increases

To lower your LSI value, add muriatic acid (can be found in pool supply stores). Consult the calculator above to determine the target pH value (recommended range is 7.2 to 7.6).

Pool Medic Home


(727) 869-SWIM

service@thepoolmedic.com



We use a formula called LSI (Langelier Saturation Index) 

ITS ALL ABOUT THE BALANCE!

ITS ALL ABOUT THE BALANCE!

LAB WORK

Pool Medic © swimming pool supplies service repair inground pool equipment

STORE HOURS

Mon - Fri:  9:03-5:00

Saturday:  9:07-1:00

Sunday:      Closed


  • TOTAL DISSOLVED SOLIDS*
  • PHOSPHATES*
  • NITRATES*
  • BORATES*
  • COPPER*
  • IRON*
  • FREE CHLORINE​
  • TOTAL CHLORINE
  • BROMINE
  • PH
  • TOTAL ALKALINITY
  • CALCIUM HARDNESS
  • CYANURIC ACID
  • SODIUM LEVEL