Reducing chlorine additions

May 1, 2007
199
Denver, Colorado
So, at a CYA of 45, you loose approximately 50% of your CL per day. The recommended minimum is 2.9 and goal is 4.6. Assuming you attain the 4.6 in the morning, you would be at 2.3 by evening and be below your minimum. To stay above the min. you would have to add CL more than 1 x per day. Does anyone do this manually? I don't have an auto anything.

It would be nice to not have to test and add CL every day. Is it true that at a CYA of 80, you can bring the pool to a FC of 9.1 and loose only 10% per day and still be above the minimum of a FC of 5.8...4 days later?!

I started out with a CYA of just over 50 and now tested it at just under 40 due to splashout and am thinking of making an adjustment.
 
You should use an off-line chlorine feeder like the Hayward cl-220. Put a few tabs in it and set it on low. That will give you a continuous level of 1-4ppm of free chlorine. Add Sodium hypochlorite (aka bleach or liquid chlorine) as needed. The Trichlor tabs that you put in the feeder will lower the ph and raise the Cyanuric acid. The sodium hypochlorite will raise the ph and it has no cyanuric acid. Adjust the usage of the trichlor and the bleach based on controlling the free chlorine, ph and cyanuric acid.
 
PoolOwnerNumber9 said:
You should use an off-line chlorine feeder like the Hayward cl-220. Put a few tabs in it and set it on low. That will give you a continuous level of 1-4ppm of free chlorine. Add Sodium hypochlorite (aka bleach or liquid chlorine) as needed. The Trichlor tabs that you put in the feeder will lower the ph and raise the Cyanuric acid. The sodium hypochlorite will raise the ph and it has no cyanuric acid. Adjust the usage of the trichlor and the bleach based on controlling the free chlorine, ph and cyanuric acid.

I don't recommend this unless you have a very short pool season and backwash frequently. Bleach does not cause your PH to go up in the long run, but trichlor will cause your PH to go down. So you will need to be constantly raising your PH. Also, even supplementing with bleach, the CYA level will eventually get too high and cause problems.


There is a pool service that uses very high CYA levels and adds huge amounts of chlorine once a week. I also know several people who use CYA levels around 80-100 and add chlorine every other or every third day. These approaches have advantages, but when something goes wrong they can be a real pain. High CYA levels make it very difficult to fight algae once you have it. High CYA levels can also make it difficult to be sure of your PH, since the required high FC levels tend to affect the PH test. It can also be difficult to accurately measure CYA levels above 90, since the common CYA test will report levels over 100 as 100.
 
Shelley N said:
Yeah. I have an above ground pool and don't think I'm a candidate for a SWG.

You're still a candidate for a SWG... Many people with AG pools have Saltwater Systems, and hopefully I will soon be one too. If you don't want to spend the big money that most SWG's cost, consider an Intex SWG, they are cheap(usually around $150.00) and you can use them on any pool, not just Intex ones.

HTH,
Adam
 

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Tabs (pucks, tri-chlor) can be very useful in a maintaining a pool.........if you understand them (and the CYA/chlorine relationship).

Like most chlorine delivery vehicles, the side effects are the "gotcha's".

It's been said a bunch before but BBB is no "secret" method but rather simply understanding your pool water and learning to test and adjust accordingly.
 
PoolOwnerNumber9 said:
You should use an off-line chlorine feeder like the Hayward cl-220. Put a few tabs in it and set it on low.


This right here is the trick, I think. Set it on low.

I've used a Hayward trichlor feeder successfully for three seasons now, set at 1/8 of its full capacity. I start with 0 CYA (pool freezes solid), add enough granular stabilizer when I open at the end of April to get it to 30 ppm, and finish the season at the end of October with a CYA of between 50 and 60. The pH holds steady at 7.5 all summer. I start with a TA of 110 which drops to 70 by season's end. I do have a lot of splashout, probably 1/3 of the entire pool volume over summer, and I backwash once a month.

The chlorine loss varies between 0 and 2 ppm per 24 hr period with many contributing factors. I add liquid chlorine approximately every other day and am just now on the second 3 gallon carboy. I'll probably have to buy one more before we close.

If used conservatively and smartly tab feeders can work very well in conjunction with the BBB approach. You need a good test kit and use it daily, log readings, understand how weather and swimmer load can change your pool chemistry, understand when a fluctuation is critical and know how to fix it.

Backyard pools are not a set-it-and-forget-it venture. They do require care and attention to detail, but really only 5 minutes a day.
 
Trichlor has it moments, the most obvious one being new plaster pool startups. Trichlor is also good for people with a short swim season who backwash regularly and tend to lose all their CYA over the winter. There are also other special case situations where higher FC, higher CYA, and lower PH are all desierable for a short period of time.

Other than that, trichlor is not generally a good idea for routine use. Trichlor is very easy to use until it doesn't work any more (because CYA gets too high). Very few people are aware that you need to constantly raise your FC target as the CYA level goes up. Trouble invariably ensues, though it might be a long time coming.
 
PoolOwnerNumber9 said:
You should use an off-line chlorine feeder like the Hayward cl-220. .
The Hayward CL200 series of chorinators are known in the industry as having problems. They tend to clog and then are either all the way open or all the way closed. The Rainbow (Pentair) chlorinators are not only more dependable but are actually less expensive!
 
JasonLion said:
Other than that, trichlor is not generally a good idea for routine use. Trichlor is very easy to use until it doesn't work any more (because CYA gets too high). Very few people are aware that you need to constantly raise your FC target as the CYA level goes up. Trouble invariably ensues, though it might be a long time coming.


Which is borne out by many of the posts here where seemingly indefeatable algae is often the result of a too high CYA and too low FC and those, in turn, are the results of trichlor usage.

The thing is, many pool builders install the feeders as part of the package and new pool owners (we all were there at one point) like the convenience. Had I not found the Pool Forum three years ago I would be in that very place: a trichlor feeder set by the builder to nearly its full capacity and a jar of test strips. I shudder to think of the condition my water would be in had I just gone along with that program.

I like the work we're doing here on TFP, offering an alternative to automatic puck feeders, helping people learn how to gain control over their pool because knowledge is power, while also allowing that trichlor systems can be used successfully if their usage is based on the skill sets provided here.
 
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