Drained Pool, Need Help On Adding Chlorine

[AMG]

In my spa I used the dichlor (with stabilizer) to get it up to proper CYA level, then I switch to liquid chlorine bleach (6%) so I don't continue to raise the CYA.

My pool I just drained and re-filled. I read the page TFP - How to Chlorinate your Pool. I have a LOT of chlorine pucks left over so I was wondering what Chem Geek (or anyone else on here) recommendation would be to get my CYA up to proper levels. Should I just use up my chlorine pucks over the next few weeks. Otherwise if I buy stabilizer in the jugs and bring me up, then I will have wasted all these pucks, right? If that is not the right approach, I will gladly scrap these pucks, buy stabilizer, then switch to liquid chlorine (bleach). To start me off with my fresh water, I got the TA correct, then PH fell right in, CH is good, then I used a bag of chlorine shock powder, filled up 3 pucks in my chlorinator and the water is about 3ppm right now. CYA is not even measurable in my Taylor 2005 test kit YET.

[Anka]

I would get some stabilizer and add 1/2 the amount recommended by the Pool Calculator for your water volume. Since all of your other chems are balanced I would then put the pucks in the chlorinator and let them maintain the chlorine while adding CYA. Do you have enough CYA testing reagent to keep track of the levels?

Conversely, you can add the stabilizer now and just go with bleach, and keep the pucks for when you're out of town and not able to maintain the pool. I use mine at the beginning of the season until I have the CYA level I want and then go with just bleach, holding the pucks until I need to run the chlorinator unattended.

[AMG]

I would get some stabilizer and add 1/2 the amount recommended by the Pool Calculator for your water volume. Since all of your other chems are balanced I would then put the pucks in the chlorinator and let them maintain the chlorine while adding CYA. Do you have enough CYA testing reagent to keep track of the levels?

Conversely, you can add the stabilizer now and just go with bleach, and keep the pucks for when you're out of town and not able to maintain the pool. I use mine at the beginning of the season until I have the CYA level I want and then go with just bleach, holding the pucks until I need to run the chlorinator unattended.

Yeah that may be the way to go. I have a 32oz huge jug of the stuff to test CYA. The little ones that came with my Taylor 2006 test kit dont go far. I think the idea of keeping the pucks for when I am on vacation. Right now with the pucks in there, they are releasing chlorine and some CYA, but I bet if those pucks ran out, the chlorine would be gone quickly with no CYA.

So how long will the pucks last? I know liquid chlorine loses its effectiveness. Will the hard chlorine pucks last a lot longer?

I'll get some stabilizer this weekend and add 1/2 of what pool calculator calls for, then continue with pucks for a bit longer then go to liquid bleach method, same ive been doing for my spa.

[polyvue]

I would get some stabilizer and add 1/2 the amount recommended by the Pool Calculator for your water volume. Since all of your other chems are balanced I would then put the pucks in the chlorinator and let them maintain the chlorine while adding CYA. Do you have enough CYA testing reagent to keep track of the levels?

Conversely, you can add the stabilizer now and just go with bleach, and keep the pucks for when you're out of town and not able to maintain the pool. I use mine at the beginning of the season until I have the CYA level I want and then go with just bleach, holding the pucks until I need to run the chlorinator unattended.

Yeah that may be the way to go. I have a 32oz huge jug of the stuff to test CYA. The little ones that came with my Taylor 2006 test kit dont go far. I think the idea of keeping the pucks for when I am on vacation. Right now with the pucks in there, they are releasing chlorine and some CYA, but I bet if those pucks ran out, the chlorine would be gone quickly with no CYA.

So how long will the pucks last? I know liquid chlorine loses its effectiveness. Will the hard chlorine pucks last a lot longer?

I'll get some stabilizer this weekend and add 1/2 of what pool calculator calls for, then continue with pucks for a bit longer then go to liquid bleach method, same ive been doing for my spa.

Much, much longer... perhaps several years if kept sealed and free of humidity/moisture.

Anka has given superlative advice and it sounds like you're on the right track.

32 oz of melanine, huh? If your sample size is 7.5 mL that should last a couple of years! I've only seen that size sold at a decent price at Taylor and PoolWeb. Do you have another source?

[AMG]

Much, much longer... perhaps several years if kept sealed and free of humidity/moisture.

Anka has given superlative advice and it sounds like you're on the right track.

32 oz of melanine, huh? If your sample size is 7.5 mL that should last a couple of years! I've only seen that size sold at a decent price at Taylor and PoolWeb. Do you have another source?

I think i may have 16oz. It came in last week, havent used it yet as I have some of the tiny little bottles left over. Either way its a big jug and it'll last a long long time. They have 128oz for $30. I have bought a lot of stuff from this website and been very satisfied

http://www.poolcenter.com/taylor_test_kit_reagents.htm

[Anka]

I just recently bought a pint of CYA reagent from amatoind.com. The reagent was $6-something and the shipping was $5-something. Those little refills available through the vendor where I bought my TF-100 kit aren't useful to me. Those of us who utilize a combination of pucks and bleach need to test for CYA more frequently and it makes sense to buy in larger quantities. Amatoind is a good company to work with: Personal e-mails from Mary to keep one informed of order status and the shipping slip comes with a handwritten note from her saying thank-you for the order. Prices are reasonable and the selection of items and quantities offered is perfect for my needs.

As to how long do pucks last? I'm on my third season of a large bucket of trichlor and have not noticed any degradation of product or effectiveness. Yesterday's CYA test came in at 40 ppm. I'll probably run another 2 weeks on the pucks and then switch to liquid chlorine. I test CYA weekly during the first few weeks of the season.

[AMG]

I just recently bought a pint of CYA reagent from amatoind.com. The reagent was $6-something and the shipping was $5-something. Those little refills available through the vendor where I bought my TF-100 kit aren't useful to me. Those of us who utilize a combination of pucks and bleach need to test for CYA more frequently and it makes sense to buy in larger quantities. Amatoind is a good company to work with: Personal e-mails from Mary to keep one informed of order status and the shipping slip comes with a handwritten note from her saying thank-you for the order. Prices are reasonable and the selection of items and quantities offered is perfect for my needs.

As to how long do pucks last? I'm on my third season of a large bucket of trichlor and have not noticed any degradation of product or effectiveness. Yesterday's CYA test came in at 40 ppm. I'll probably run another 2 weeks on the pucks and then switch to liquid chlorine. I test CYA weekly during the first few weeks of the season.

when you talk about 'the season' you must have a pool where you drain it each year? I just drained and re-filled and i dont plan on doing it again for a few years since I am in california.

[Anka]

No. I have a water season which goes from the end of March to the end of December and a swim season from the end of May to the end of September. Between December and March the pool is frozen solid.

I test and treat the water from the end of March to the end of November.

[AMG]

No. I have a water season which goes from the end of March to the end of December and a swim season from the end of May to the end of September. Between December and March the pool is frozen solid.

I test and treat the water from the end of March to the end of November.

If it is the same water that is never drained, then where does the CYA go? I thought that once it is there, it remains. Once you get it where you want, it shouldn't go down too much. As water evaporates the CYA remains, you add more water, but the CYA is already there, right?

[Anka]

Excellent question: Where does the CYA go? We don't know.

There have been many reports of CYA having disappeared over winter, especially in closed pools. There are some thoughts that it may be consumed by bacteria or algae but no-one seems to know for sure.

I end the season with about 60ppm CYA. When I close I bring the FC level to 20 ppm, shut off the pump and disconnect the plumbing. The pool is not covered over winter. By the end of December it's frozen solid and won't be fully thawed until the end of March/first week of April. At that time there is no measurable amount of chlorine or CYA in the water. Where the CYA goes nobody knows.

This is why I can afford to use trichlor pucks at the beginning of the season and have to add stabilizer granules early on. It's important to carefully monitor the CYA level and stop adding it (in any form) once the target level has been reached. My target is 50 ppm; SWCG pools should be operated at 60 ppm. Overdosing with CYA does mean a partial drain and refill for most pools.

If you're interested in the relationship between chlorine and CYA there's an excellent thread here.

[polyvue]

Excellent question: Where does the CYA go? We don't know.

There have been many reports of CYA having disappeared over winter, especially in closed pools. There are some thoughts that it may be consumed by bacteria or algae but no-one seems to know for sure.

Yes, the loss of significant amounts of CYA over the winter seems only to be noted in areas that require closing. The CYA in my unclosed pool showed no diminution for almost 5 months (daily filtering but no swimming.) I seem to recall a thread discussion where this was attributed to ammonia* but can't place it. Also, I have noticed that in summer there is a small but measurable loss in CYA from my SWG chlorinated pool from month to month; it needs occasional replenishment. A certain amount is obviously lost through splash out. But I think the loss is higher than can be explained by this. The only other chemical added regularly is muriatic acid - no bicarbonate of soda, calcium chloride etc., but I'm unaware of any benchmark (standard) to be able to use for comparison. There is little in the way of borates in the pool (< 5 ppm), so my comparative reference is rather weak in that I'm judging its loss relative to the zero demand for bicarb and calcium. The chemistry interactions - for CaCO2 and other compounds - are too daunting for me to be able to conceive of a working theory.

* EDIT My memory was foggy. Ammonia is a by-product of one type of decay, but there are several possible mechanisms for degradation of CYA. Two are summarized in the following thread.

http://www.troublefreepool.com/degradation-of-cyanuric-acid-cya-t8880.html

Edited May 4, 2010 by polyvue

[PaulR]

Here chem geek has documented that a survey of hot tub owners shows a loss of about 5ppm CYA per month. He attributes this to a slow oxidation of the CYA by chlorine (see various degradation mechanisms here). Pools with high summer temps ought to see some CYA loss for the same reasons as tubs, but not quite as fast because they're not quite as hot.

--paulr

[polyvue]

Here chem geek has documented that a survey of hot tub owners shows a loss of about 5ppm CYA per month. He attributes this to a slow oxidation of the CYA by chlorine (see various degradation mechanisms here). Pools with high summer temps ought to see some CYA loss for the same reasons as tubs, but not quite as fast because they're not quite as hot.

--paulr

Lovely!

Paul, thanks for resurrecting the 2008 thread that covers degradation of CYA. I know I'd read this before. Re-reading it also reminded me of yet another possible mechanism contributing to the inexorable rise of pH in some pools and provides a basis (even if provisional) for understanding what happens to CYA. That oxidation of CYA via chlorine is temperature dependent (higher temps leading to a higher rate of oxidation) fits with what I've observed in my own pool.