What Chemicals are Needed for Pools?

chemicalsKeeping your swimming pool clean and clear can be a tough job, especially if you don’t have the right chemicals. Keep the basics on hand for regular maintenance as well as anticipated water problems.

My little blog post today lists below all of the pool chemicals that every pool owner should be familiar with; at the end is a short list of pool chemicals that should be kept in stock.


CHLORINE-TABLETSThese are the chemicals that you use to keep water sanitized and disinfected. There should be a constant level of chlorine (or bromine) in the water at all times, without a lot of peaks and valleys.

TriChlor: 3” tabs, or 1” tabs or sticks. With cyanuric acid. Add them to a chlorine floater or a installed chlorinator.

DiChlor: granular. With cyanuric acid. Powdered form acts quickly to chlorinate pools, fountains or spas.

Bromine: 1” tabs. Great for spas; works better in hot water, and can be regenerated by shocking. More pH stable as well.

Cyanuric Acid: Liquid or dry chlorine stabilizer. Protects chlorine from damage by UV rays. Small amounts are added to dichlor and trichlor; add extra if pool was drained, to maintain 30-50 ppm. Drain some water and refill if CYA levels get much higher than 50 ppm.


pool-shocksOxidizers are the secondary sanitizer, used every few weeks to kill algae and bacteria. Chlorine or Non-Chlorine shocks are in a powdered form, just open the bag and pour it into the pool.

Calcium  Hypochlorite: Cal Hypo pool shock is used to quickly sanitize pool water, boost chlorine levels and kill algae. Works best with a low pH level of around 7.2.

Chlorine Free Shock: Granular potassium monopersulfate (non- chlorine). A fast acting oxygen based sanitizer that burns clean with no residue, and you can swim right after treatment.

Lithium Shock: Lithium hypochlorite. This one is great for pools with liners because it won’t bleach the liner, and also dissolves right away so is safe to swim right after treatment.

Water Balancers:

pool-chemicals-water-balancersTo keep your water in balance, you should test the pool several times per week for chlorine and pH levels, and adjust as needed. Test total alkalinity every few weeks or if you have pH troubles, and test calcium hardness and cyanuric acid levels every month.

pH Increaser: Granular Soda Ash. Increase pH when levels fall below 7.2 ppm. 1 lb of pH Up will raise pH about 1-click, from 7.2 to 7.3 for example, in 10000 gals of pool water.

pH Reducer: Granular Sodium Bisulfate, or Dry Acid. Reduce pH when levels rise above 7.6 ppm. Also used to lower total alkalinity.
1 lb pH Down will lower pH about 3-clicks, from 7.8 to 7.5 for example, in 10000 gals of pool water.

Alkalinity Increaser: Granular Sodium Bicarbonate. Raise total alkalinity when levels fall below 80 ppm. 1 lb of Alkalinity Increaser will raise TA by about 10 ppm, in 10000 gals of pool water.

Calcium Hardness Increaser: Granular Calcium Chloride. Raise Calcium hardness when levels fall below 150 ppm. 1 lb of Calcium Increaser will raise CH by about 10 ppm, in 10000 gals of pool water.

Chlorine Neutralizer: Granular Sodium Thiosulfate. Use if chlorine concentration becomes too high. 1 lb of Thiosulfate will lower free chlorine levels by about 10 ppm, in 10000 gals of pool water.

Chemical Combo Packs: Pool Chemical packages you can choose from that include the tablets, shock, algaecide, and stain away you’ll need to carry you through your entire pool season. These are a great way to get yourself started with the bare essentials.

Specialty Chemicals:

specialty-chemicalsThere are many specialty chemicals that can come in handy when unexpected problems arise, or to keep your pool looking it’s best. This is one of the largest categories of pool chemicals, for every possible pool problem!

Algaecides: Some are copper based, most are non-metallic polymers. Helps to prevent algae from growing in your pool – use pool shock to kill algae, and algaecides to keep it from returning.

Clarifiers: Clarifiers coagulate tiny particles into bigger particles that can be trapped in the pool filter. Flocculants attract particles into heavy clumps that sink to the floor for vacuuming to waste.

Enzymes: Enzymes like Pool Perfect break down oils and other forms of non-living organic contamination from the water, removing scum, oils and odors.

Filter Cleaners: Used to clean sand, D.E., and cartridge filter elements to keep your filter working well. Removes oils, minerals, metals and other filter clogging gunk.

Metal Magnets: Sequestering agents are used to lock-up trace metals from the water and keep them in solution, so they don’t stain your pool surfaces.

Phosphate Removers: Products like PhosFree break down phosphates in the water. Phosphates are the primary food source for algae. Without food, algae can’t survive.

Stain Removers: Prevents or removes surface stains, scaling, and colored water due to minerals and metals in the water. We have over 15 different pool stain chemicals.

Tile & Vinyl Cleaner: Works great to help remove oils and grease build up around the water line, or on furniture, skimmers, diving boards and slides. Pool Cleanser won’t affect pool chemistry.

Start Up Kits and Closing Kits: When it comes to opening and closing the pool, or stocking up for the season, check out our chemical value packs that contains everything you need!

What Chemicals Should be Kept On-Hand?

As a minimum, the average pool will want to keep the following chemicals on hand – even if you use a salt chlorinator, you will need these other pool chemicals from time to time:pool chemical kits

  • Chlorine tablets and pool shock
  • Pool pH Up and/or pH Down
  • Test strips or test kit

Every pool will also need other chemicals to raise calcium, cyanuric or alkalinity levels, usually once per year – and clarifiers, enzymes, algaecides can be an important part of the overall routine, or are especially handy when you’re in a pinch!

12-categories-of-pool-chemicalsThere’s lots to learn, with 12 categories of pool chemicals – you won’t need them all; but it’s important to understand what they do, so that when you do need them, you know which chemical to use!

Safe swimming!

Christine Silvestri
InTheSwim Staff Blogger