Pool Chemicals Explained

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Pool Chemicals Explained

Postby DohenysPoolSupplies » Thu 20 Sep, 2012 11:25

GUIDE TO BEING A POOL PRO: Which pool chemicals to use and when to use them!


What are sanitizers?
Sanitizers are used to kill bacteria and inhibit/control the growth of viruses, algae and organic contaminants. The two most common pool water sanitizers are chlorine and bromine.

What is chlorine?
Chlorine is a disinfectant and the most popular sanitizer used in pool water. Chlorine levels are determined with a test kit and measured in parts per million (ppm). The ideal chlorine residual (the remaining chlorine after all reactions and dissipation have occurred) in pool water should be between 1.0 and 3.0 ppm.

Doheny's DIRECT PURIFICATION SYSTEM provides more effective chlorine at an even lower price. How do we do it? By cutting out the middle man! Our competitors’ chlorine travels across the country just to sit on a shelf at a store before you pick it up. Doheny's chlorine arrives fresh because we ship DIRECTLY to your home the same day you place your order. Fresh chlorine from Doheny's cleans your pool water more effectively than deteriorated chlorine that has lost its potency. Plus, Doheny’s chlorine is made in the USA!

What is bromine?
Bromine is an alternate sanitizer to chlorine. Bromine levels are also measured using a test kit. The ideal Bromine residual is 3.0 ppm. Bromine is not as harsh as chlorine on skin, eyes, hair and swimwear, and does not produce a chlorine odor. Bromine dissolves slower than chlorine and is more effective in hot water. It also recycles itself when new bromine is added!

How do I use a sanitizer?
Doheny’s recommends sanitizing your swimming pool with stabilized 3” chlorinating tabs, 1” chlorinating tabs, skimmer sticks or 1” bromine tabs. These can be conveniently dispensed by placing them in a chlorinator (or brominator), floating feeder, or skimmer basket. If you prefer to sanitize by pouring directly into the water, then Di-Chlor Chlorinating Granules are a good choice (they should not be used in a chlorinator). You may need an extra dose of chlorine or bromine in order to satisfy the initial demand of the water. Use your test kit often to check chemical levels and adjust your dispenser as needed to increase or decrease the flow. Temperature, pool usage, rainfall and pH are factors that affect the amount of sanitizer you need. Higher water temperatures, heavy pool usage and heavy rainfall all result in the necessity for increased chlorine or bromine.

Can I convert my pool from chlorine to bromine?
Yes. You should let the levels of chlorine drop to .5 ppm and then start adding bromine to your feeder.


What are Balancers?
Balancers help to maintain various levels of your pool’s water chemistry. Balancers are used with sanitizers to maximize the performance of chlorine, and help prevent algae growth and cloudy water. They can also reduce high chlorine levels. Performing a quick and simple water chemistry test before problems arise can prolong your pool’s life and provide you season after season of enjoyment!

What is pH and How Do I Maintain Proper pH Levels?
pH Level is the acid/base content of water, and is the most important factor in your pool water’s chemistry. The pH scale ranges from 0 to 14 with 7 being neutral. You should strive to maintain pH levels between 7.2 and 7.6 in order to prevent eye/skin irritation, and damage to the pool’s surface and equipment. Use Doheny’s pH Plus to raise the pH level and Doheny’s pH Minus to lower it.

What is Total Alkalinity?
Total alkalinity is the measure of certain minerals in the water. These minerals act as buffering agents which allow you to easily control your pH. If alkalinity is not within its ideal range, then it can cause eye and skin discomfort. Under normal conditions, a measurement of 100 to 150ppm is ideal in a plaster pool. A reading between 125 to 175ppm should be maintained in painted, vinyl or fiberglass pools. If the alkalinity is too low, then use Doheny’s Alkalinity Up. To lower alkalinity, then use Doheny’s pH Minus or muriatic acid.

What is Calcium Hardness?
Calcium Hardness measures the levels of calcium and magnesium minerals in the water. These exist naturally in all water, but levels vary greatly across the country. An acceptable hardness level is from 225 to 300ppm hardness for plaster pools and 175 to 250 ppm for vinyl, painted and fiberglass pools. Low levels of calcium create corrosive water which can damage equipment. It is important to test your pool’s calcium hardness monthly with a pool water tester. Raise hardness levels by using Doheny’s Calcium Plus. Lower hardness levels by using Doheny’s Calcium Hardness Reducer.

What is Stabilizer?
Stabilizer is a chemical that prevents the sun’s UV rays from prematurely dissolving your chlorine. Doheny’s Stabilizer reduces sanitizer consumption by up to 50% and should be added to the pool at its opening if needed. It is important to test your stabilizer level first because it stays in your water indefinitely. If stabilizer was added in the past, then you generally add more based on the additional gallons of water added to the pool this season. Too much stabilizer can cause cloudy water.


What is shock treating your pool?
Shock quickly raises the chlorine level in your pool. Various bacteria and organic pollutants called chloramines can resist normal chlorination and result in contaminated and cloudy water. Algae buildup is highest during hot weather and periods of heavy pool usage. Weekly treatments with Doheny’s Shock will break up these contaminants. You can add powdered or liquid shock to cement and gunite swimming pools; however, it is important to make sure that the treatment won’t bleach your pool’s vinyl liner.

When do I use shock treatment?
It is best to apply shock in the evening so it can work overnight and be down to normal levels by the next day. Be sure your filter continues to run during this time. Do not swim for 8-12 hours after adding shock to your swimming pool.

What types of shock are there and how much should I use?
Doheny's Super Shock - GREAT VALUE! This fast acting shock features 68% calcium hypochlorite as an active ingredient to help clear the most contaminated pools. Recommended dosage: 1 lb/10,000 gal.

Doheny's Super Shock Plus - EXTRA STRENGTH! Super powerful shock with 73% calcium hypochlorite for crystal clear pool water. Fast acting with minimal residue effectively kills bacteria, stops algae in its tracks and destroys organic contaminants. Recommended dosage: 1 lb/10,000 gal.

Doheny's Lithium Premium Shock - FAST & NON CORROSIVE! Super strong shock will not fade or bleach your vinyl liner! Destroys most major organic waste, yet won't leave deposits on fittings or other plumbing. Recommended dosage: 1 lb, 10,000 gal.

Doheny's Di-Chlor Chlorinating Shock - Di-Chlor with 56% available chlorine kills algae and will rid your pool of unsightly algae spots. Ideal for use in vinyl lined, fiberglass or colored plaster surface pools. Recommended dosage: 1 gal/10,000 gal.

How can I make my shock more effective?
Doheny's Oxidizing Shock
Use with your favorite shock! CHLORINE FREE! The active ingredient, potassium monopersulfate, effectively keeps water clear while controlling contaminants. Safe for all pool surfaces. Recommended dosage: 1 lb/10,000 gal. every 10 days.


What are Algaecides?
Algaecides are used to kill existing algae that survive general chlorine dosages and prevent algae formation. Algae are aquatic organisms that grow rapidly in pool water when there is a combination of warm water and lack of chlorine or other sanitizers. The most common types of pool water algae are green, pink, black and mustard.

When Do I Use Algaecides?
The initial signs of algae growth are slipperiness on the pool’s surface, green or cloudy water, and colored spots on pool walls or floor. Algaecides are best used as a backup to your normal sanitation program.

Which Products Prevent Algae From Forming?
Doheny's Algaecide 60 - Our most popular algaecide! Algaecide 60 treats up to 200,000 gallons! Use once a week to prevent algae growth. High doses even kill existing algae! Does not contain metals, so it won't stain surfaces. Non-foaming. Highly concentrated formula! Recommended dosage: 2-4 oz/10,000 gal.

Doheny's Algaecide 50 - Get the job done right with this non-metallic, non-staining algaecide! Prevents and kills all types of algae and won't leave residue. Recommended dosage: 1.25 oz/10,000 gal.

Doheny's Algaecide - Save money with this economically-priced algaecide. Prevents most forms of algae, including common green and mustard algae. Non-foaming formula will not cloud pool. Recommended dosage: 8 oz/10,000 gal.

Which products are best at killing visible algae growth?
Doheny's Super Algaecide Plus - Super strong algaecide even kills persistent yellow mustard algae in pool water. Powerful formula contains 7% chelated copper which prevents common green, pink and black algae growth. Will not foam or cloud water. Amazing strength--treats up to 200,000 gallons! Effective in all parts of the country. Recommended dosage: 2 oz/10,000 gal.

Doheny's Total Algaecide - Extra-strength formula kills ALL types of stubborn algae, including black, mustard, pink and green. Non-foaming, non-staining formula significantly clarifies pool water. Prevents new growth for 90 days. Recommended dosage for every 3 months: 16 oz/10,000 gal. Recommended dosage for treating visible algae growth: 12 oz/10,000 gal.


What Are Enzymes and How Do They Work?
Enzymes are the all-natural way to clean the film of body oil and suntan lotion that clouds your pool water and leaves a ring of scum around your pool. Enzymes speed up the rate that organic material is broken down and consumed. In the human body, enzymes help us digest food and eliminate toxins. This is why doctors recommend enzyme-rich foods such as yogurt, figs and bananas. Your pool water is a fertile environment for living organic matter. Enzymes destroy oils, fats, detergents, dirt, pollen, and other types of organic material. Enzymes are used to clean up oil spills, so you know they will work on the small amount of oils that produce scum in your pool. Enzymes are also effective in preventing foaming in pools and spas.

Which Enzyme Product Do You Recommend?
Doheny’s Nature's Magic – Doheny’s exclusive formula uses natural enzymes to clean oil and eliminate the water line ring from your swimming pool. Adding Nature’s Magic weekly to your pool water will prevent scum build-up, thus you will spend less time scrubbing. Enzymes also linger in the filter so this product helps to keep it clean! Read instructions carefully and dilute accordingly. Recommended dosage: 10 oz/10,000 gal once a week.


What are Clarifiers?
Clarifiers are used to remove particles from the pool that are too small to be caught in the filter system, thus causing cloudy water. Flocculants or clarifying agents will cause these particles to clump to each other, making them larger, so they can be removed from your water through vacuuming or filtration.

Which Clarifier is Best For My Swimming Pool?
Doheny's Water Clarifier Plus - Great value! Even the best maintained pools have tiny suspended particles that can escape your pool’s filtration system. Doheny’s Water Clarifier Plus binds those particles together so they are large enough to be trapped. You are left with sparkling, clear blue pool water and you save big money because you bought direct from Doheny’s. Bottles feature child-resistant caps. Highly concentrated for quick and effective results. Recommended dosage: 2 oz/10,000 gal.

Doheny's Water Clarifier - Less concentrated than Doheny’s Clarifier Plus and more economically priced. For general maintenance to achieve crystal clear water. Recommended dosage: 4 oz/10,000 gal.

Doheny's Extra-Strength Flocculent - Our product thoroughly settles suspended debris (carbonates, silica, dead algae and spore-like materials) to the pool’s bottom so they may easily be vacuumed out. Doheny's Extra-Strength Flocculent does not contain corrosive aluminum or ammonia, will not affect pH, and is safe for all pools and filters. Use with normal pH and free chlorine levels. Recommended dosage: 8 oz/10,000 gal.

Stain Removers

What are Stain Removers?
Stain removers are used to remedy stains, scale, discoloration and cloudy water caused by metals coming out of a solution (precipitate) in the water. NOTE: Stain remover is most effective when residual chlorine is dropped to .05 ppm or lower, and pH is between 7.0 and 7.1.

What is Scale?
Scale is when the precipitated metals form hard, white deposits on the pool walls, floor and equipment.

What is Stain?
Stain is when the precipitated metals have color and are deposited on the pool walls or floor. Precipitated metals may also remain in the water causing cloudiness and discoloration. To remedy this condition, a sequestering agent is required. This will help your filter remove precipitated metals.

Which Stain Remover is Best For My Swimming Pool?
Doheny's Extra-Strength Metal Out –An easy, inexpensive solution to remove stains, scale and discoloration caused by metals in your water. This powerful and concentrated sequestering agent is ideal for areas with excessive metal and mineral problems. Recommended dosage: 2 oz/10,000 gal.

Doheny's Metal Out - Regular use of this less concentrated formula is ideal for controlling general stains and helps maintain a sparkling clean pool. Easily eliminates scum and mineral deposits. Recommended dosage: 4-6 oz/10,000 gal.

Doheny's Stain Remover - Professional strength granular acid, yet safe for all pool surfaces. Helps remove stains, residue and spotting. Recommended dosage: l lb/10,000 gal. Pre-dissolve in 3 gallons of water, distribute throughout the pool and watch those stains disappear!


What are cleaners?
Cleaners are used to clean unique pool surfaces and devices that become spoiled by chemicals and organic materials that come in contact with your swimming pool.

Which type of cleaner is best for my swimming pool?
Doheny's Filter Cleaner & Degreaser - For cleaning sand and/or D.E. Filters. Prevents channeling. Just pour into your skimmer. Effectively reduces the amount of time and work you spend on pool maintenance. Recommended dosage: 8 oz/100lb sand.

Doheny's Cartridge Cleaner - If you have a cartridge filtration system, then this cleaner will help keep it working efficiently. Doheny’s Cartridge Cleaner is specially formulated to remove dirt, soap, grease and film. It effectively cleans all cartridge filter elements. Follow directions carefully.

Doheny's Foam Away - Nobody likes to see the water in their pool or spa foaming! Doheny’s Foam Away takes care of the problem instantly! Doheny’s defoamer eliminates and prevents foaming and excess suds. Works both in pools and spas, and is sanitizer compatible. Recommended dosage: 1 capful/500 gal.

Doheny's Tile & Vinyl Cleaner - Spend less time cleaning the walls and bottom of your pool, and more time enjoying poolside fun with this special formula. Removes grease, grime and scale, and eliminates water lines! Apply with a wet sponge or a clean cloth and scrub the surface. Rinse the area with pool water after application to remove grime entirely.

Doheny's All Surface Cleaner - Spray on to remove stubborn stains quickly! Powerful mildew deterrent. Doheny’s non-abrasive formula works well on pool and spa covers, plastic and canvas patio furniture, umbrellas, awnings, solar blankets and other deck accessories.

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chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2381
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Pool Chemicals Explained

Postby chem geek » Fri 21 Sep, 2012 19:46

I suggest you and others read the Pool School. Your advice is not good in some cases. For example, it gives a 1-3 ppm Free Chlorine (FC) recommendation with no regard to the Cyanuric Acid (CYA) level. The active chlorine level that kills bacteria and algae and oxidizes bather waste is proportional to the FC/CYA ratio (known science since at least 1974 as described in the paper linked at the top of this post) so specifying an FC level without a corresponding CYA level is inappropriate. If one continues to use stabilized chlorine products, then the CYA builds up and the FC/CYA ratio gets too low (unless you proportionately raise your FC target) and algae can grow. The following are chemical facts independent of concentration of product or of pool size:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.

If one uses the appropriate FC level for their CYA level, then they can prevent green and black algae growth regardless of algae nutrient (i.e. phosphate and nitrate) level. In this situation, one never has to use algaecides, phosphate removers, clarifiers, flocculants, enzymes or do any weekly or regular shocking. This is the case for nearly 40,000 pool owners at Trouble Free Pool, nearly 15,000 at The PoolForum, and many on this forum.

In my own 16,000 gallon pool, I only use 12.5% chlorinating liquid and some acid and it costs me only $15 per month in chemicals to maintain my pool. I have a mostly opaque electric safety cover so my chlorine usage is a relatively low 1 ppm FC per day, though the pool is used every day for an hour or so and longer on weekends. More typical pools my size that are open to exposed sun use around 2-3 ppm FC per day so would cost perhaps $30-45 per month. I started out 9 years ago using Trichlor pucks in a floating feeder and ran into problems when my CYA got to 150 ppm the middle of the second season. That's when I learned about the real science of pool water chemistry and ditched the Trichlor and never looked back. You too can do the same.

As for some of your pool chemical products, were you going to tell people that "Alkalinity Up" was the same as Arm & Hammer Baking Soda? Were you going to tell people that "pH Up" was the same as Arm & Hammer Super Washing Soda (careful: NOT the laundry detergent) and that instead of pH Up you could use 20 Mule Team Borax to raise the pH with half the rise in Total Alkalinity (TA)? Were you going to tell them that instead of "pH Minus" that they could use Muriatic Acid and that doing so would avoid increasing sulfates in the water that can ultimately lead to plaster/hardscape deterioration (see this thread)? Were you going to tell them that instead of Calcium Plus that one could use DowFlake or Peladow? See this post for detailed links showing that the grocery/hardware store products have identical ingredients to the pool store versions but are often far less expensive.

If you're going to shamelessly post in a forum for pool owners promoting your website selling pool chemicals, then you're going to get responses making sure that you do not intentionally withhold materially important information that consumers need to know to make informed purchase decisions.

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