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pool calculators

All pools and spas need maintenance.

We at Hines Pools & Spas are here to help you determine just what kind and amount of maintenance your pool or spa needs. Below are step by step instructions to determine your pool’s volume which determines the amount of chemicals needed to keep your pool or spa crystal clean. All you need are the dimensions of your pool. Most spas are so small they have little affect on the volume, so for now, we will not worry about spas.

Unless the pool builder provided you with the exact volume of your pool, you need to estimate the volume. It is not a difficult process but you will need to do a little measuring. And remember this will be an estimate.

Rectangular Pool

The rectangle is the easiest to estimate as the formula is the Length X Width X Average Depth X 7.5 

    • Where 7.5 is the # of gallons of water in one Cubic Foot.  
    • For Average Depth, the easiest way to calculate is to take the shallow end depth PLUS the deep end depth and divide by 2.
    • If you have a pool with varying length or width, just use an average. Think of it as laying a rectangle on top of an odd shape, some areas may cover the deck and some areas may leave part of the water area uncovered – use the best length and width to cover the majority of the pool
    • For Example, if your pool is 28ft long and 14ft wide with an average depth of 4.5ft, the calculation would be 
      • Volume = 28 x 14 x 4.5 x 7.5 = 13,230 gallons.

Circular or Oval Pools

There are not too many true circular pools out there unless it is an above ground pool. But in case you have one, the formula we use is the same for Oval or Circle – Length X Width X Average Depth X 5.9

    • Where length is the long side of the oval and width is the narrow side of the oval. 
    • If you have a true circle, the length and width would be the same number
    • For Example, if your pool is 32ft long and 16ft wide with an average depth of 4.5ft, the calculation would be 
      • Volume = 32 x 16 x 4.5 x 5.9 = 13,594 gallons.
    • For a 16ft wide circular pool the calculation would be
      • Volume = 16 x 16 x 4.5 x 5.9 = 6,796 gallons.

Kidney Shaped Pool

This is similar to the rectangle, but has a narrow section and a wide section so you need to find the average width using the widest part of the shallow area and the widest part of the deep area so the first formula is to find the Width (Width 1 + WIdth 2) X .45. Once you have the width you can use the rectangle formula –  Length X Width X Average Depth X 7.5 

    • For Example if your pool has the shallow end widest width of 8ft and the deep end widest width of 16ft, with a length of 30ft and average depth of 4.25ft, the calculations would be 
      • Avg width = 8 + 16 = 24 X .45 = 10.8
      • 30 x 10.8 x 4.25 x 7.5 = 10,327.5 gallons

Langelier Saturation Index

The Langelier Saturation Index (LSI) is a formula developed from studies conducted by Dr. Wilfred Langelier in the early 20th century. The LSI is the basis for water balance and saturation, and this article will try to explain how it works in a simplified way. This is complex science, but very helpful to know as a pool owner or operator. We recommend managing your pool chemistry using LSI and one of our partners, Orenda Technologies has developed a fantastic calculator to help you calculate and manage your pool chemistry using the LSI. Click the calculator to be taken to their website and working version of the calculator. From there you can also download the Orenda LSI Calculator App to your phone!

We can Deliver Your Pool Chemicals

If you need chemical delivery please use our online store to order what you need.

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