determine how much chemicals to add to pool

Determining the Right Level of Chemicals to Add to Pools

by | Jun 9, 2023

If you’re going to have a pool in the US, where better than the Sunshine State, where we have mild to humid days year-round? Not only do residences here have enough land for an outdoor pool big enough to accommodate everyone at each backyard hangout, but at-home pools offer the perfect alternative to Orlando water parks. However, you should know how to determine the right level of chemicals to add to pools in preparation. 

Classic Marcite knows when temperatures near 100 degrees, you just want to cannonball into the refreshing water, but it won’t seem so invigorating without the appropriate steps. Our trained team has completed over 100,000 projects with residential pool resurfacing in Orlando, FL, and is well-versed in everything from building to maintaining a pool. 

For the best swimming experience, take our advice and consider the below factors.

Calculating the Volume of Your Pool

Dumping in random amounts of chemicals won’t suffice since it’ll either prove too much or too little. So, to receive the best measurement for your unique pool, calculate the volume of your pool in cubic feet and multiply that by 7.5, since there are 7.5 gallons in each cubic foot of pool water. 

Still, since not all pools have straight sides for easy measurements alongside different depths, we’ll explain how to get an accurate number. 

Simple Polygonal Shapes

Basic shapes like squares and rectangles with straight sides and edges are the most straightforward to measure, especially if the pool comprises a single depth. In these cases, measure the length and width of the perimeter and multiply the two together. Next, note the depth and multiply that with the new number for the cubic footage of your entire pool and multiply that by 7.5 to receive the total gallon.

For a gradually sloping pool floor, follow the same process when finding the pool’s surface area with length times width, but when you get to depth measurements, measure the shallow and deep ends add the two numbers, and divide by two. Then, take the surface area, multiply it by this average depth, and multiply by 7.5. 

However, the best way how to determine the right level of chemicals to add to a pool with an immediate change in depth should be split at the dropoff and measured as two or more separate pools. Once you get the volume of both sides, add them together to find the total gallons of water. Then, using the chemical instructions, add the appropriate amount per gallon. 

Curved Pool Shapes 

Pools with arches or circular or oval perimeters are not as straightforward to measure length- and width-wise, so instead, measure the length from one end of the pool to the other, crossing over the water to get the diameter. Then, divide that number by two to get the radius before squaring it. Finally, multiply the radius squared by pi (3.14), the average depth, and then by 7.5 for total gallons. 

Unusual Shapes 

If you have a pool shape you can’t decipher, obtaining measurements is a bit trickier but not too different from what we did previously. Organic shapes comprise numerous smaller shapes, like circles, ovals, squares, and rectangles, so simply divide your pool into the smaller shapes you see, usually giving you five or six sections. You should also separate the pool according to depth.

Once you outline your pool, use the measurements in the previous sections to find the volume of each part before adding them together. If you end up with decimal numbers in your calculations, round to the nearest foot for the closest measurement. 

Types of Chemicals at Your Disposal

You need sanitizers that add about 1.0 parts per million of chlorine to the water, alongside water balancers and specialty chemicals to keep your pool clean. 


Chlorine usually comes in tablets, the two most common sizes being a one-inch, six-ounce table for smaller pools and a three-inch, eight-ounce table for larger ones. This chemical also comes in one-pound bags of pool shock that add up to 9 ppm of chlorine per 10,000 gallons of water. 

Knowing how to determine the right level of chemicals to add to a pool includes calculating 7,500 gallons of chlorine for every 120,000 gallons of water for one ppm. 

Water Balancers

Not only should you ensure that your pool is clean without being overly abrasive by adding the following, but also store your chemicals safely to prevent spills and accidental inhalation:

  • pH increaser or decreaser raises or drops the pH .2 to .3 points on the scale with each pound of chemical added to 10,000 gallons of water. Add as much as necessary to maintain a pH level of roughly 7.5.
  • One pound of alkalinity increaser adds eight ppm to every 10,000 gallons, and you need 80 to 120 ppm for this volume. 
  • One pound of calcium hardness increaser also places eight ppm into every 10,000 gallons and should range between 200 and 400 ppm for this amount.
  • One pound of cyanuric acid stabilizer adds 12 ppm for every 10,000 gallons and should give you 30 to 50 ppm for 10,000 gallons. 

Specialty Chemicals 

Specialty chemicals focus more on visible issues with water and pool appearance. For instance, if you notice anything from cloudy water to scale and algae growth on inner walls, consider adding pool algaecide, clarifiers, enzymes, phosphate remover, stain and scale removers, and others. 

We Have the Classic Touch!

When pool owners use little to no chemicals, it creates a breeding ground for viruses and bacteria, leaving you and your visitors prone to sickness. Likewise, placing too many chemicals proves harmful to human health, causing eye, skin, and lung irritation and leading to respiratory illnesses like asthma, particularly after swallowing or breathing in the chemicals. 

Therefore, always know how to determine the right level of chemicals to add to pools for the best results. For more on understanding pool chemistry for your pool size or for renovations and resurfacing, count on Classic Marcite in Orlando, FL, and surrounding areas. Call our family-owned and operated company at (407) 521-6260 for a free estimate today!

About Mike Folta
Mike Folta has served the clients of Classic Marcite for more than 15 years. He has 20+ years in the pool industry servicing large hotels and theme parks in the Greater Orlando area, as well as expertly turning backyard pools into an island oasis.