Borax and CYA

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Your water can be clear and no visible algae but you still have stuff growing in your water.

Follow the SLAM process to a tee until you pass the 3 criteria.

Your water is not clear. You have visible algae and it's from not completing the slam process and high CYA and not maintaining FC level needed to SLAM it and keep it clean.

You have an over stabilized pool. Your experience is normal. Reduce CYA and complete SLAM.
 
Yes-I will do first thing. I thought that cya made the chlorine a lot less effective and thereby requiring more FC becasue of high cya. I drained about 10 % and refilled today and will check. It also poured rain today and I will drain some more tomorrow and report full set of data. I used the wrong term but think I am correct right??
 
Here are latest results after drain pool from last night rain and the previous 5% drain--the results this morning after time for water to mix is cya 80-90 using 50% mixture of city water and x 2 Total A is 60 FC is 3.0 hardness is 200 I have not used any chlorine in three days so Chlorine has been removed alone with cya. Pool is clear .
 
FC (chlorine) is consumed/use when the FC kills and oxidizes the algae (and other organics) and by the sun.

CYA protects the FC from the sun but make is slower to oxidize algae. When your FC is below the minimum for a given CYA, it does not kill the algae fast enough.

So, with 3FC the algae grows fast enough to be visible on the walls and the FC become lower as it slowly kills a diminishing amount of algae. When the FC is near 7FC, the FC kills algae at a rate a little faster than the algae grows and your pool maintains a clear appearance. At 30FC (SLAM) the FC rapidly consumes the algae and clears it out of the pool. This is why we use a high FC to clear the pool of algae and the 4-7 FC to maintain a pool that is clean to start.
 

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mraiteri123 said:
OL Thanks--I got it now. I was always told that a swg clorine level usually needs to be a lot lower than salt water--around 2-3 but will do as recommended. As cya comes down, I should be able to maintain enough chlorine to prevent aglae.
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Just about everything you need to know you can find in Pool School. It can be a bit overwhelming at first but just stay with it and it'll all sink in eventually.

FC doesn't need to be "a lot lower" with a SWG, just somewhat so given the difference in recommended CYA levels. For instance, a quick glance at The Chlorine/CYA Chart shows that for a CYA level of 70 the minimum to target FC levels for a non-SWG pool is 5 to 8. For a SWG pool those levels drop to 3 to 5. Roughly a decrease of 40%. However, for most Non-SWG pools the recommended CYA levels range from 30 to 50, but for SWG pools the range changes to 60 to 80, and the recommended FC levels WITHIN those CYA ranges are basicly the same...

...Non-SWG..., mid-range recommended CYA level of 40, Minimum FC Level 3ppm, Target Level 5ppm
......SWG......, mid-range recommended CYA level of 70, Minimum FC Level 3ppm, Target Level 5ppm

So, as techguy suggests, its pretty much ALL about the CYA and Free Chlorine relationship. Get a good handle on that and you're golden. :paddle:
 
You know, I thought a little about this and in some ways there is some truth but it is buried. The active level of FC may be lower in an SWG due to the effects of CyA. A SWG usually has a higher CYA than an LC (liquid chlorine) pool. If the CYA is zero, the FC is 100% active so when you have 3fc, you have 3fc active free chlorine. When you start adding CYA, some of the FC becomes less active when it binds to CYA, so it lasts longer but it is less active. So in a 70CYA, a pool with 5FC will have less than 3 FC active FC and more than 2FC bound to CYA in reserve. It doesn't take much active FC to kill algae. The goals set at TFP allow most users to safely maintain their FC levels above the point where algae grows and have it stay that way until the next time they add chlorine.

I know we could discuss the actual amounts but the important thing is to understand the effects of CYA on chlorine. This is what BBBis built on and what we use at TFP
 
I have read the pool school but have always been told that cya should be 30-50 to stabize a pool. Why do you want to keep chlorine at such high levels. I understand that with higher cya, you need more free chlorine but shouldn't to goal be to have just enough cya to stabize the pool and not make the chlorine less effective by having too much cya. The same thing with borax--there is a recommended level for borax and anymore makes it less effective according to TFP experts on borax. What is optomina cya and FC for SWG to using the minimun amount of chemicals to keep the prefect chemistry.
 
There is no optimum, there are pluses and minuses for lower or higher CYA levels. The chart is the recommended range for best performance, of course every pool is different.
 
I have a SWCG, and I try to keep my CYA at 70 (I don't let it drop below 60). I try to keep my chlorine between 5 and 7.

I have borates at 50 ppm. But I believe you really are placing too much emphasis on borates. Borates are optional, and something you shouldn't even be thinking about until you have everything else dialed in. Borates have no effect on CYA or chlorine, and have no effect on required CYA and chlorine levels. Most on this forum don't bother with borates at all, and have perfectly maintained pools with crystal clear water.
 
The levels suggested in pool school are set to the optimum levels to ensure a safe sanitary pool while using the minimum amount of chems to do that.

You are incorrect about the borax. Borax is used to adjust the pH without affecting the TA much. Using more doesn't make it less effective.

With CYA, using more doesn't make it less effective either it means that you have to have a higher FC to achieve the same effectiveness as with a lower level, however, there is a tradeoff. If you have too low of a CYA level you lose more FC to sunlight and wind up using more chlorine than you need to. In the case of an swg pool, using too low a CYA level results in the swg having to replace more FC than it should and it winds up using up the cell and/or letting the FC get too low during the day and allowing algae to grow, which means using a lot more chlorine trying to get rid of it.
 
mraiteri123 said:
I have read the pool school but have always been told that cya should be 30-50 to stabize a pool. Why do you want to keep chlorine at such high levels. I understand that with higher cya, you need more free chlorine but shouldn't to goal be to have just enough cya to stabize the pool and not make the chlorine less effective by having too much cya.
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You need to get out of your head the idea that the FC level means anything with regard to chlorine's strength. It doesn't as a parameter by itself. When CYA is present, MOST of the chlorine (around 97%, depending on the actual FC and CYA levels) is bound to CYA and nearly inert -- less than 1/150th as reactive as the unbound chlorine. The amount of active chlorine is roughly proportional to the FC/CYA ratio (that's a result of equilibrium chemistry) which is why as the CYA level gets higher the FC must be proportionately raised to have the same active chlorine level. It is this active chlorine level that kills algae and pathogens, oxidizes bather waste, and is also what oxidizes swimsuits, skin and hair.

The "minimum FC" for each CYA level given in the Chlorine / CYA Chart for non-SWG pools has the same active chlorine level as a pool with 0.07 ppm FC and no CYA. For SWG pools, it's the same active chlorine level as a pool with 0.04 ppm FC and no CYA. So this idea you have of "high levels" of chlorine is completely inaccurate. The FC is the amount of chlorine in reserve or in the reservoir bound to CYA and that is released quickly as needed when the active chlorine level drops getting used up killing algae or pathogens or oxidizing bather waste or getting broken down by sunlight (the chlorine bound to CYA also gets broken down by sunlight, but more slowly). CYA significantly moderates chlorine's strength and that's a good thing with regard to chlorine being less harsh on bathers and pool equipment, outgassing less, producing fewer disinfection by-products, and lasting longer in the presence of sunlight, but too low an FC/CYA ratio will allow algae to grow. The levels in the Chlorine / CYA Chart are set to have chlorine kill green and black algae faster than it can grow regardless of algae nutrient (phosphate, nitrate) level.
 
Bama Rambler said:
The levels suggested in pool school are set to the optimum levels to ensure a safe sanitary pool while using the minimum amount of chems to do that.

You are incorrect about the borax. Borax is used to adjust the pH without affecting the TA much. Using more doesn't make it less effective.

With CYA, using more doesn't make it less effective either it means that you have to have a higher FC to achieve the same effectiveness as with a lower level, however, there is a tradeoff. If you have too low of a CYA level you lose more FC to sunlight and wind up using more chlorine than you need to. In the case of an swg pool, using too low a CYA level results in the swg having to replace more FC than it should and it winds up using up the cell and/or letting the FC get too low during the day and allowing algae to grow, which means using a lot more chlorine trying to get rid of it.
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____________________________________________________________________________________________________________________To Rambler and Jason

OK so to be clear, you think my FC should remain above 5 ( what the chart calls for to match cya) and forget what the people say about swg chlorine levels. You guys are experts and not selling anything; so I trust your opinion and that's why I added borates because an expert suggested it ( most pool companies never even (can't) test for it) Not just becasue it saved chlorine but it supposely makes the water sparkle and look clean and clear and it sanatizes. How high is too high of a chlorine for swimming one or two people. The data on bortes does say to not excedd 50 --is that not correct? I always understood you didn't want too much chlorine in the pool--right??

One other question. I had a small swg pool in Florida maintained by a pool company and when testing the pool water with a regular test kit--just chlorine and PH and TA -- I never saw the water turn yellow indicating there was chlorine but no algae. The pool guy had to adjust ph but that's all--never any algae --keep salt at 3300 level Why no visalbe chlorine with salt water. Stupid question is there a differnt chlorine with salt swg that with a chlorine pool. SWG benefits are no bleaching effect, no burning eyes that you get with chlorine pools. I am very confused Help please See below about the borates
____________________________________________________________________________________________________________________

See below--a question from a member and answer from Jason Lion


There is one pool store in my area that promotes Borates in your pool. They even have a program where they guaranty no algae if you follow their program. If you get algae, they will personally maintain your pool at their expense to get the problem resolved. Pretty good endorsement for Borates I'd say.

Here's the catch. They say the normal 35-55 ppm borates are not enough in this area (Houston, TX). I'm guessing long days of hot sun are the reasoning. For them to give the guaranty, you have to maintain between 70 and 90 ppm.

1) I have resisted using Borates because I have a dog and cat that do drink some pool water. I've convinced myself from my research that the 30-50 ppm is OK...but I'm certainly not convinced that at 70-90 it will still be OK.

2) I'm adding borates more for the look and feel, and less for the algaecide quality (because I've found algae isn't a problem if you keep the FC/CYA/pump times in check). With that said, is more borates better to prevent algae...or are they just selling more product by requiring you to be at higher levels?

Thanks in advance for any feedback.



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JasonLion Post subject: Re: Suggested Borate LevelsPostPosted: April 29th, 2011, 2:14 pm
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We don't recommend raising the borate level above 80, and have never run into a case where going over 50 was required or even helped noticably.

Are you sure your aren't mixing up borates with cyanuric acid? Most of what you just said makes a lot more sense if you/they are talking about the cyanuric acid level, which is very much related to the amount of sunlight your pool gets, while borates are not especially related to sunlight.
 
Since you have a swg, and assuming it's working, you should use the recommended levels for an swg pool from the chlorine/CYA chart or the pool calc. The recommendation not to exceed 50 ppm borates is due to the minute possibility of affecting a pet from them getting all their drinking water from the pool and because we don't recommend it for algaecidal effects, but for pH stabilization.


Chlorine from an swg is the same chlorine from liquid or tablets or powder. It's all the same chlorine. The fact that you had no chlorine showing up means that the pool wasn't sanitary even though you had no algae. There are a lot of reasons a pool might not get algae. The service could have been using algaecides, adding "shock" weekly, etc.. Just because it doesn't have algae doesn't mean that it's sanitary.
 

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