Wight Water Pool Service
Pool Chemistry
Wight Water's HomePay for ServiceFAQ, Hours and LocationPool ChemistryPool ServiceGreen CleanCloudy PoolsPool FilterMotor and Light RepairPool and Spa RepairWight Water Fall/Winter TipsHelpful Pool VideosFree Local DeliveryEmployment

Call today 559-645-1969

Pool Chemistry

What is the difference between test kits?
Yes, the first stumbling block to most pool owners: Why are there so many different test kits and what do they all do? Which one should I buy? Should I buy the one that is the cheapest to save money?  Or how about the most expensive one?  It's always the best choice, right? Should I buy the one with the drops so I can look like a pro when my spouse and kids watch me out the window? Will they all give me the correct readings I need to make my damn pool water clear? Why do they make so many different test kits?
When attempting to purchase the perfect test kit these are thoughts that travel through most home owners head. 
If these questions Sound familiar, let me help.

In our retail store in Madera Ranchos we carry four different kits:

We carry the 2 in 1 kit which consists of 2 Reagents or liquids to test Total Chlorine and pH. Basically, this test kit to me is useless, unless you just want to use the pH side of it because it's easier to read, which I do like to do. Yes, I carry it because a lot of homeowners are used to this type of test kit and don't want to change. This test kit is called an OTO Test Kit. 
What is the difference between Free Chlorine and Total Chlorine? 
 Free Chlorine is the Chlorine you want in your pool. It is the usable Chlorine that kills Bacteria in your water. Total Chlorine measures Dead Chlorine and Free Chlorine. Dead Chlorine, or Chloramines, is used up Chlorine. Chloramines are what puts off a strong chlorine odor, burns your eyes, and irritates skin. When you only test for Total Chlorine in your pool you don't know how much of it is actually in usable form.

The next test kit that most homeowners use is a 4 in 1 Test kit, which again tests total chlorine (Free and Dead Chlorine together), pH, and Alkalinity. 
Ph is a scale that tells you how acidic or base your water is. If your pH is too acidic (below 7.2) it will start destroying things in your pool just like acid does. If too high, Scale or heavy particles will drop out of suspension in your water. Keeping your pH between 7.2 to 7.6 will help you avoid these problems. Also, the higher your pH is, the less effective the killing power of your Chlorine is. Chart 1 shows you this relationship.
Alkalinity is important; it's what helps keep PH to stay in balance and stops it from bouncing. A good range to keep it at is between 80 to 120 ppm. If it gets out of balance it can do the same damage to your pool as pH.  
The third and fourth kits we carry are Test Strips. The first kind tests for Total Chlorine (TC), Free Chlorine (FC), pH, and Alkalinity.
The other kind I carry is mostly used by professionals. I don't believe homeowners need this test kit because they can just take a water sample into their local pool store and get the two extra readings that these test strips have on them, which is Calcium Hardness, and CYA (stabilizer, conditioner).

The Hardness test measures the amount of Calcium you have in your water. Basically, if your Calcium is too low (below 150 ppm) then your water may starve for Calcium and start drawing it out of your pool walls (cement, plaster), or the grout on your tile. If this starts to happen, your pool will form craters in the plaster, the structure will be weakened, and your grout may loose the adhesion necessary to hold your tiles in place. Tour TH or Total Hardness level should be between 150-400.
If your calcium is too high, your water will become over saturated with it and the calcium will start dropping out of suspension adhering to anything it can: tile, pool walls and floor, plumbing, filter elements, media, etc.
Cyanuric Acid or CYA also known as Stabilizer, or Conditioner; works as a Suntan Lotion for your water. The right amount will help protect your Chlorine from getting eaten up by the UV rays of our sun. Most experts recommend a level between 30-60 ppm. If too low your Chlorine will get removed from your water too quickly, if too high it will not be as effective. My two cents... Most homeowner use a lot of products that have Stabilizer in them, so I like to start a pool with readings at the lower end because the only effective way to remove high CYA is by draining the pool. Yes, there are now enzymes out to help lower CYA, but it's still controversial of how effective they are, so I'm not going to attempt to bore you about those. CYA should be between 30-80ppm no higher.
 Which test kit should you buy?
The quick answer is: I like to use the test strips because it's fast, and easy. Also, it usually gives you everything you need to make the right adjustments to your water. The test strips that I would recommend for homeowners are the ones that test Free Chlorine, Total Chlorine, pH, and Alkalinity.

Note: Once you choose your test kit the next step is to check your water.  

You'll want to check your water once a week for Free chlorine, pH, and Alkalinity. Once a month I recommend getting your water checked for CYA and calcium hardness during the swim season (water temp 65 +degrees). If at any time both your CYA or Total Hardness (TH) test comes up high (above 450) you really should drain your water to avoid calcium dropping out of suspension and ruining pool finish, filter, tile, plumbing, etc. If not, there is an alternative, but it's a little controversial how well it works.   


Before adding any chemicals to your pool always read the labels. Be careful because not all chemicals are the same typically the ones you buy from big box stores and hardware stores will have a lower amount of chlorine and more fillers. Pool chemicals should be rotated on shelves just like they rotate your milk. The longer they sit on the stores shelves the less effective they will be in your pool. If you need any help with which chemicals to add and how much just bring a water sample into our store located in Madera Ranchos CA of avenue 12 in Maywood Center. You can bring in your water in any clean plastic water bottle or jar.

What Chlorine should I Use?
In order to answer that question, you first have to understand what is in the different forms of Chlorine you buy.

There are four different types of Chlorine people typically use in the valley:

Cal-hypo Shock which is normally between 50-75% active Chlorine and as the label says it has Calcium in it. It's usually the cheapest form of shock and it's normally sold in hardware stores, grocery stores, etc. The one we sell is above 70% concentrate. However, most stores you'll find that it is not as concentrated and has a lot more fillers inside. This shock typically dissolves the quickest, so it is usually used when cleaning up a green pool, and vinyl liner pools.
In the Valley, a lot of Calcium is naturally introduced into our pools, so I don't recommend using too much of this shock. When your water becomes over saturated with Calcium, Scaling starts to form and water can become cloudy. This shock has a pH of 10.5-11.5; So, it will raise your ph.

Di-Chlor Shock is normally between 60-99% active Chlorine and has added Stabilizer. The one we sell is 99% Sodium Di-Chlor. If you use a lot of tablets in your pool, you wouldn't want to use this chlorine too often, because pretty soon your waters CYA level will be off the chart, which means your Chlorine wouldn't be as effective. This chlorine has a pH of about 6.8 to 7.0 so it doesn't change your pH too much.

Liquid Chlorine is usually between 8-14% Chlorine. However, the longer it sits on the shelf, the less concentrated it becomes. Our Chlorine is rotated and delivered daily to help maintain its strength and effectiveness. This chlorine has a pH of about 13; So, it will raise your ph.

Tri-Chlor or Tablets will be between 85-99% Chlorine. The tablets we carry in our store are 8oz slow dissolving tablets with 99% Chlorine with added Stabilizer (not recommended for pools with high CYA levels). These Tablets have a pH of 2.5 to 3.0; We don't recommend putting them directly in your skimmer basket. Tablets should never be used as the only form of sanitizer because they dissolve too slowly, they will make your pool extremely acidic, and raise your CYA level.

Now that you have a little knowledge about the different forms of chlorine, this is what I would recommend adding: Non-Chlorine shock to revive your Chlorine, then liquid Chlorine to raise the Chlorine in your pool, and Tablets (not too many) to help maintain your Chlorine. This will help keep your pH pretty well balanced but you may have to add some acid to lower it on occasion. Make sure you check your chemicals once a week and adjust as needed. After a heavy use of your pool I would recommend checking them the next day.

Wight Water Pools, Inc.