Confused about CYA, Stabalized vs. Non-Stabalized CL

[CactusPool]

The pool is in the early phase of construction and I'm trying to learn as much as I can before opening day. My pool installer sold me on an automatic tablet feeder for use of Tri-chlor tablets. Once the pool reaches the undesirable CYA levels and I switch to a chlorine without a stabilizer, will the "excess CYA" provide UV protection? Perhaps I'm overly concerned, but I'm not happy that this stabilized chlorine solves the UV problem and in so doing creates a CYA problem. Further, I don't like the idea of partially draining the pool to correct for the CYA concentration. Please note that this pool is in extremely sunny Bullhead City, Arizona. It's often hotter here than Death Valley: July and August, over-night lows of 90+ and daytime highs of 115+. I read on a pool maintenance site that CYA will breakdown, but slowly over a long period.

 

[kimkats]

Re: Confused about CYA, Stabalized vs. Un-Stabalized CL

HI! I am SO glad you found us! We will take the mystery out of pool care for you. Here is a good stater read:

TFPC for Beginners

Now here is the "big boy" that goes a little deeper:

Pool School - ABCs of Pool Water Chemistry

Here is a chart to help you understand the different levels for you water. I have this one printed out and inside my test kit lid:

Pool School - Recommended Levels

Now the next thing we need to talk about is your test kit. Find out what the PB will be providing. Look in my siggy below for the test kit we use and love. It has ALL of the tests you need to care for your pool. We will help you compare the test kit from the PB and the one you need.

we got ya and understand where you are coming from. It is a LOT of info. but we will break it down to chewable bites LOL

Kim

 

[JVTrain]

Stabilized chlorine means that chlorine is bound to another molecule to allow it to exist in a solid form. It's either cyanuric acid (trichlor or dichlor), calcium (cal-hypo) or lithium (lithium hypochlorite). Tablets in a feeder are always made of trichlor. For every ppm of FC (free chlorine) that it adds to your pool, it also adds 0.6 ppm of CYA. The FC is consumed by organics and sunlight, the CYA is not. Continual use of trichlor tablets will cause CYA levels to rise too high to maintain sanitation. The higher your CYA level, the higher FC level needed to maintain a clean pool. You need CYA to protect your FC from sunlight but too much makes it difficult to sanitize.

Check out the [FC/CYA][/FC/CYA]. In your area, you're likely going to want a CYA level of 60 ppm. If it's lower (on initial fill) you'll burn up your FC very rapidly due to loss to sunlight (UV). If it's too high (after using tablets for an extended period), you'll need to maintain high FC levels and your FC losses will also be fairly high.

I would not use the tablet feeder for any extended period. Use only for vacations or times when you'll be away, know that using it will raise your CYA level. CYA does break down slowly over time, but likely only about 10 ppm over several months, depending on pool conditions. CYA is only lost otherwise by draining or splash out. The only cost effective form of manually adding chlorine is bleach aka liquid pool shock. Otherwise, I would look into adding a salt water chlorine generator.

 

[tim5055]

Your pool installer has done you no favors by recommending a tablet feeder. In it's natural state, chlorine is a gas. Many large commercial pools actually use gas injection systems to chlorinate their pools. Now, to change chlorine into something we can use at home it needs to be bound to something. The "somethings" that are commonly used are stabilizer (also known as CYA), calcium, lithium, or --- get this water. All of these add a little salt to your water, but they add something else. Cal-Hypo add calcium, Tri-Chlor and Di-Chlor (tabs and most granules) add stabilizer, Lithium hypochlorite adds lithium and liquid chlorine adds - water.

All of these things can be bad for your pool (except the water) in large quantities. The stabilizer helps shield the chlorine form UV degradation, but at higher levels it also impairs the ability of chlorine to do it's work. The higher the stabilizer level you have the higher the amount of chlorine you need. Too much calcium and you start to get scaling on the walls and floors of your pool.

Calcium, this leads to a second comment to you. You live in a high calcium area. Meaning the water that comes out of your hose is high in calcium naturally. Most pools in the southwest US have slowly rising levels of calcium (CH is how we refer to it) which needs to be watched also.

For a new pool I would be eliminating the tab feeder and going with a salt water chlorine generator. Please do not be confused as many are that "salt" is a sanitation method. Salt is placed in a salt water pool to create chlorine. The same chlorine I was talking about above. In a salt pool there is a device, called a salt water chlorine generator (SWG or SWCG). Through a chemical reaction in the devise chlorine gas is produced in the water flowing through it. This constantly adds chlorine to the water. Then, through he process of sanitizing your pool the chlorine breaks back down into salt and the cycle continues.

All of this leads to testing. Order a TF100 test kit. That probably will give you enough reagents for a couple of years normal use.

 

[GaryT58]

+1 what's been said above. Tablets are convenient until you have a real issue. As said, as the CYA level increases, so must your FC level. So you will reach a place where the tablets will not be able to add enough FC to actually sanitize because of the high CYA. As said, tablets can be great if you use regular chlorine (i.e. bleach) normally and will be gone for a while and no one is available to add chlorine. Plus with adding yourself, lowest cost method. Minus - must do so daily (but once pool is stable you will get a "feel" for your pool - but still need regular testing)

Or there is a stenner pump system - where you have bleach in a tank and a pump will put some in at a level you choose/adjust. So you still need bleach, but less daily intervention. A minus is that you have to find where to store tank - do not want where really hot/sun as bleach strength can break down very quickly at high temps (i.e. 90+).

Then there is the Salt Water Chlorine Generator (SWG) - where you add salt initially to your pool. You only need to add again to make up for salt lost due to water loss. The SWG uses a "cell" to convert the salt water into chlorine. You can adjust the output level to meet what your pool needs. Plus - works well without much intervention (do have to adjust as temps go up/down). Minus - most expensive to initially install.

You can find many postings about +/- of each of the above. You can always start with plain chlorine on your own and change if you want later to stenner or SWG, but it is easier, especially if you are not able to install yourself, to get it all done at the beginning.

Welcome,
Gary

 

[Captain 776]

In my less than expert opinion, I think an SWG pays for itself in the long run, less maintenance (but not maintenance free) better quality of water when you are in balance.
I have an SGW and very happy with it.
Check it periodically to make sure scale is not accumulating between the plates of the element. This will happen.
Mine is clear plastic, I can shine a flashlight in the end and see if it is time to clean it.
Very easy to remove the element and soak it in Cell Cleaner or your own 20% Muriatic Acid solution.

One thing I can say for this site, based on my experience here, listen to the advice from the Experts and Moderators. The majority here think the pellet feeder is not the way to go as eventually it can lead you to a bigger problem.
if it is in your budget, and possible go change.
Ask the question for others to give you the Pro's and Con's of an SWG.