3" chlorine tabs without CYA

Yes, and no, but really no. There isn't anything that dissolves slowly and doesn't contain CYA. You can get tablets made out of cal-hypo, but they dissolve way to quickly to be used in the same way trichlor tablets are used and contain calcium.
 
Disinfecting chorine is unstable and there are very few ways to stabilize it enough to transport it and still have it work in the pool. There are really only six forms available: bleach, trichlor, dichlor, cal-hypo, lithium-hypo, and chlorine gas. Each has advantages and disadvantages, there is no perfect combination.

The best approach I have seen is a SWG, which creates the chlorine on site, so no transportation is required.
 
There are only a few forms of solid chlorine and only one is very slow dissolving, making it useful in erosion feeders. This is trichlor, which is a chemical made from chlorine and cyanuric acid (a chlorinated isocyanurate). The problem with this slow dissolving form of chlorine is that it will cause CYA levels to rise since once the chlorine is used up the CYA remains. The next slowest dissolving form of chlorine is calcium hypochlorite (cal hypo) which does not contain CYA but will cause calcium levels to rise over time. It dissolves very fast in comparison to trichlor so it does not work very well in erosion feeders and cannot be used in a pressurized feeder without danger of explosion so it's usually used in a plastic coated capule or tablet that is placed in the skimmer but these only last a few days at best and leave a lot of residue behind.

All the other solid forms of chlorine (lithium hypochlorite which will not raise CYA but is very expensive to use and dichlor which will raise CYA faster than trichlor does) are very fast dissolving so they are not useful for erosion feeders.

The two forms of chlorine tht have the LEAST side effects on water chemistry are lithium hypochlorite, a fast dissolving granular that is EXTREMELY expensive to use, and sodium hypochlorite (bleach or liquid chlorine) which is not as convenient as the dry forms of chlorine but is very economical to use.
I hope this explains it.
 
waterbear said:
There are only a few forms of solid chlorine and only one is very slow dissolving, making it useful in erosion feeders. This is trichlor, which is a chemical made from chlorine and cyanuric acid (a chlorinated isocyanurate). The problem with this slow dissolving form of chlorine is that it will cause CYA levels to rise since once the chlorine is used up the CYA remains. The next slowest dissolving form of chlorine is calcium hypochlorite (cal hypo) which does not contain CYA but will cause calcium levels to rise over time. It dissolves very fast in comparison to trichlor so it does not work very well in erosion feeders and cannot be used in a pressurized feeder without danger of explosion so it's usually used in a plastic coated capule or tablet that is placed in the skimmer but these only last a few days at best and leave a lot of residue behind.

All the other solid forms of chlorine (lithium hypochlorite which will not raise CYA but is very expensive to use and dichlor which will raise CYA faster than trichlor does) are very fast dissolving so they are not useful for erosion feeders.

The two forms of chlorine tht have the LEAST side effects on water chemistry are lithium hypochlorite, a fast dissolving granular that is EXTREMELY expensive to use, and sodium hypochlorite (bleach or liquid chlorine) which is not as convenient as the dry forms of chlorine but is very economical to use.
I hope this explains it.

Ya i follow all that, and actually understand. But you would think someone would figure out a way to get us the best of both worlds. Slow dissolving tablets that do not jack up your pool chemistry :). I can wish..
 
mdhwoods said:
Ya i follow all that, and actually understand. But you would think someone would figure out a way to get us the best of both worlds. Slow dissolving tablets that do not jack up your pool chemistry :). I can wish..
That would mean developing and testing an entirely new chemical that does not exist and then getting it approved by the EPA.
 
Good discussion..

I assume the CYA rise in using pucks takes a long time? I ask because I added several pounds of CYA last year when our liner was changed (new water obviously). I keep two BioGuard smart sticks in ea skimmer at all times. My CYA is still only 30.
 
jjdurrant said:
Good discussion..

I assume the CYA rise in using pucks takes a long time? I ask because I added several pounds of CYA last year when our liner was changed (new water obviously). I keep two BioGuard smart sticks in ea skimmer at all times. My CYA is still only 30.
Depends on several factors. You have a sand filter so each time you backwash you are diluting the water. If you had a cartridge filter the CYA would rise faster since you would not be backwashing.
Bottom line is this. For every 10 ppm FC added by trichlor then you have also added 6 ppm CYA. The chlorine gets consumed but the CYA stays behind so, sooner or later, you WILL have an overstabilized pool! (FC is normally consumed at a rate of 1-2 ppm per day in must pools but it can be as high as 3-4 ppm during the heat of summer and a lot of usage so it's entirely possible for a pool to go from no CYA to too much CYA in one short swim season!)
 
waterbear said:
mdhwoods said:
Ya i follow all that, and actually understand. But you would think someone would figure out a way to get us the best of both worlds. Slow dissolving tablets that do not jack up your pool chemistry :). I can wish..
That would mean developing and testing an entirely new chemical that does not exist and then getting it approved by the EPA.

lol but we can go to the moon... :)
 

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waterbear said:
jjdurrant said:
Good discussion..

I assume the CYA rise in using pucks takes a long time? I ask because I added several pounds of CYA last year when our liner was changed (new water obviously). I keep two BioGuard smart sticks in ea skimmer at all times. My CYA is still only 30.
Depends on several factors. You have a sand filter so each time you backwash you are diluting the water. If you had a cartridge filter the CYA would rise faster since you would not be backwashing.
Bottom line is this. For every 10 ppm FC added by trichlor then you have also added 6 ppm CYA. The chlorine gets consumed but the CYA stays behind so, sooner or later, you WILL have an overstabilized pool! (FC is normally consumed at a rate of 1-2 ppm per day in must pools but it can be as high as 3-4 ppm during the heat of summer and a lot of usage so it's entirely possible for a pool to go from no CYA to too much CYA in one short swim season!)

Thanks. I plan to stick with the smart sticks for at least another year.. keeping a close eye on CYA of course.
 
Thanks. I plan to stick with the smart sticks for at least another year.. keeping a close eye on CYA of course.

I just read this older thread today because I was wondering why CYA had to be added in a convenient tablet. So, thank you all, especially mdhwoods for the great replies.

After tiling my black tile in ground spa, I stopped using tables, added a controlled amount of CYA, and I add about a cup of bleach each day, which seems to absorb the sun more compared to when it was a plaster spa. Who knew (?).

None of the other sanitizing methods mentioned are appropriate for my needs and I would also love the miracle, slow dissolving, not CYA tablet. I would also like beaming technology, as I hate driving. :-D
 
Just to add to this. Even though its 6 years old...lol

This is why in late August you usually see the green pools in the neighborhood. It happens every year. June/July everybody's pool is sparkling. Late July/Early Aug, you start to see the water become cloudy, but still decently clear. Late August, the pool stores are packed with ppl complaining about green water. I always knew there had to a reason for this, but until I found this site, I never knew what that reason was. Now it's pretty clear......(no pun intended). Ok, maybe a little....HAHA
 
Just to add to this. Even though its 6 years old...lol
Now it's pretty clear......(no pun intended). Ok, maybe a little....HAHA

Funny! Just today I asked the local pool dealer about why they didn't carry 3" tablets without CYA. He said "without chlorine?" I said "No, without Cyanuric Acid." He said he thought they could special order them for me.

Uh hu...

So yeah, even 6 years later, we all have the same questions.
 
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Re: 3" chlorine tabs without CYA

Idea:
What is the strongest liquid chlorine you can get? (12.5 best I got) if you could find some 30+ you poor in to a 1L bottle pick it 1-10 (or what ever works) times with a needle and then drop it in the chlorinator.

Bam! Matenence free for 3 days. I need to do this. Otw to see what will fit in my chlorinator :)

- - - Updated - - -

Better yet I could rig a detergent feeder from an old pressure washer in to the plumbing.
 

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