Liquid CL and 3 inch pucks for chlorination

jaindesi

Gold Supporter
May 15, 2019
125
Bridgewater, NJ
Pool Size
15000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello Experts,
I wanted to know if we can use Liquid CL/bleach along with 3 inch pucks same time. Here is the scenario:

Use liquid CL to get the water clear. Keep the FC level at the target number after SLAM is done. Than use 3 inch pucks to continue to chlorinate the pool water. I know pucks will slowly raise the CYA levels. But what if I alternate between pucks and liquid Chlorine to keep the algae away? Brush/ vac your pool once or twice a week and try to keep the organics out of the pool.

What's your take on this?
 
Last edited:
As long as you test your levels and adjust the FC based on the CYA, no issues. Monitor pH/TA as pucks are very acidic.
 
That method can not be sustained long term. Those 3" pucks will continue to add CYA along with FC. Before you know it, your CYA will be high again - and you will need to keep the FC level higher to maintain the FC/CYA ratio as shown in the FC/CYA Levels.
 
Looking at everyone's response, it's best to use Liquid Cl alone. Reason I asked about the above scenario is I purchased the two 5 gallon buckets of the 3 inch pucsk, from Sam's Club when it was on sale. It's a headache to go return so I was thinking about just using it along with liquid CL.

Like some of you said, I would have to keep tab on all the number. I am type of of guy if the pool looks clear and CL and PH numbers are in range I don't do any other work. I guess I'll return the pucks. Thank you all.
 
Looking at everyone's response, it's best to use Liquid Cl alone. Reason I asked about the above scenario is I purchased the two 5 gallon buckets of the 3 inch pucsk, from Sam's Club when it was on sale. It's a headache to go return so I was thinking about just using it along with liquid CL.

Like some of you said, I would have to keep tab on all the number. I am type of of guy if the pool looks clear and CL and PH numbers are in range I don't do any other work. I guess I'll return the pucks. Thank you all.

Pucks will keep for a long time. I had a bucket full that I had when I got my pool. I ended up using them when I would go on vacation, or away for a the weekend. I would put the pucks in a floater. It was sporadic enough that it really didn't raise my CYA over the course of time. It would go up a bit, then rain and overflow, or I would close the pool for the season and drain 6" of water or so and refill with fresh when I opened anyway. It took 2 years or so to go through them, but that is what I used them for. Now I have a SWG so there is no need for that.
 
Last edited:
  • Like
Reactions: Msch99
I use liquid chlorine solution, usually 12.5%. I also have a bucket of chlorine tabs and a floater. If CYA gets low, as it has done when we've had a lot of rain and overflow goes out into the storm drain, or if it seems to get low at the end of winter, as it's done the last two winters, I'll use the tabs in a floater for chlorination and increase CYA until it gets back to 40. I would also use tabs if I were going to be away for a few days or a week. The nominal increase in CYA for a short time is not a concern. So short version, I use the chlorine tabs for chlorination instead of adding cyanuric acid, when I need to increase CYA.
 
Here is a thread of mine that may give you some info. I was doing some testing last year with switching between pucks and bleach. I learned a lot on how the pucks work in my pool regarding CYA increase and decrease. I was surprised to learn that very hot air and water temps drop my CYA. It seemed to drop my CYA about 10 per month. But that was with very hot temps that we get every year so it would probably be different for each pool depending on your weather.

This summer I have been using pucks since May 25th and just switched back to bleach now that my CYA is where I want it. I will continue with the bleach now until my CYA drops 10 again and switch back to pucks. I like the break from lugging bleach from the store and back to the pool! But I watch my CYA to make sure it doesn't get over where I want it. But it doesn't rise that fast so I don't have to check CYA for 3 weeks to a month so far. And so far, so good. Another plus is that I don't have to add any acid. I hate that stuff so that is another plus for me. So, pucks have their place if used correctly along with checking CYA levels. Also good for being away from home.
Good luck with whatever you decide. :wave:
Sherry
 

Enjoying this content?

Support TFP with a donation.

Give Support
Good discussion on this thread. The comment about having to continually lower ph reminded me of my issue five years ago. When I first started with tfpc methodologies, I had a continual upward ph drift problem. Every three days, I'd adjust ph to about 7.3 just to have it back up at or near 8 in three days. Over and over. Kept adding MA every two to three days until I came on here and got Chem Geeks's help. My other levels were perfect. The answer was to let TA be at the level where PH stayed steady and quit drifting even as it was out of the published range. I'm still at that TA level today. Mine is at 50. Only about three PH adjustments in all the time since is all I've had to make and only one TA adjustment. Back then, the tfp published range for ta was something like 70-100 for vinyl liner pools, so every couple of weeks, I'd do a full round of tests and find my TA was low, obviously caused by the continual MA adds. I'd raise TA back up to middle range, because I was a good tfp student, but the cycle would continue. Previous to tfp, I was using pucks and didn't have the drifting ph problem. I'm guessing that the trichlor use had taken me to a balance and keep everything in line, but then switching to bleach took me out of balance. Anyway, my solution back then was to have my TA set 20 points below the recommended minimum. I didn't fully understand the chemistry but ChemGeek said my CSI was such that my TA could be as low as in the thirties, and since it came from him, I didn't question it. Nowadays, my pool type recommendation for ta is 50-90, so I'm barely in there, but that was the solution to my ph drift problem rather than using an acidic chlorine source. Some pool surface types don't allow for this low TA from what I understand though.
 
  • Like
Reactions: Msch99
I have been using 1 gal of liquid Cl and one puck in the pool every week since last year. Last year end I checked my Cya is still low and using pucks this way does not noticeably raise Cya. Using pucks seems to reduce the acid demand.
 
  • Like
Reactions: HermanTX
@gx22 How specifically do you manage testing and dosing with the 1-puck / 1-gallon liquid chlorine weekly regimen? I'm guessing that you're picking a day-per-week to add a puck to the floater; then testing and targeting FC on some sort of regular scheduled dosing regimen, and that averages out to one-gallon add per week; or is it something far different from what I'm thinking?

In my case, if I were do add-in a puck, I wouldn't think it would change my liquid dosing technique all that much. In my case, the amount of liquid use per week varies greatly throughout the season. Right now, I'm dosing 2 1/2 to 3 ppm, or 29 ounces per day or 203 ounces per week; but early and late in the season, I dose only about 1 ppm per day to stay in target range; so at that point I'm down to about 68 ounces per week or about 1/3 of what I'm using peak season.
 
  • Like
Reactions: HermanTX
My pool has a solar cover on most of the time. Occasionally if Cl is too low, I add a gallon mid-week. Before I didn't use pucks I often need 2 gallons of liquid Cl per week at peak season.

Somehow the Cya increase by pucks seems to have dissipated so I don't notice it increases. I use pucks because I have inventory and it reduces the acid demand. My pool is about 20k gallons.
 
@gx22. Okay, so your method is not really a modified TFPC method to help maintain cya with pucks while liquid dosing daily like I first understood it to be. It's more of a modified traditional method, because you're letting FC fluctuate out of range using pucks, at least occasionally by your own omission, and then super chlorinating when you find the FC to be low. TFPC never allows for that, as one must test very often and ensures staying above the minimum seven-and-a-half percent FC/CYA 24/7/all-season, which is probably the most important tenant of TFPC. Please don't misunderstand my motive here. My point was/is not to criticize what you're doing, and if it's working for you I'm happy. My point was/is only to understand your methodology in order to maybe learn something new. I wouldn't have to do this for my pool anyway, because my CYA stays in range for about three months once I set it to 40 and so its easier for me just to go about three months; test and reset cya with stabilizer once or twice per year; but I can see how adding a puck could counter react a pool that's losing CYA quickly when added to the daily dosing regimen of liquid and would also lower the daily volume of liquid chlorine to reach target each day, and lastly it could help keep PH down if one has a PH drift problem. My answer to the PH drift problem that started only after I switched to liquid from pucks was to let my TA drop via acid doses until I reached the point where PH never drifts. My PH has stayed constant now for three years, but in order for that to work, my TA has to be left at or about 50.
 
I know the question was centered around the 3" pucks, but I wanted to offer up my story for this year. Last year around Oct, my pool pump seized. I knew this was an issue because the bearings were squealing all swim season last year. Also, this was my second set of bearings that I put in the pump in the last 13 years, so definitely due for a new pump. Well, the swim season was over and I did not replace the pump, but the air temperature/water temperature turned cold for the new fall/early winter season. I still did not replace the pump, the pool remained stagnant until May of this year (7 months). During this time, the pool went from a beautiful blue, swimmable color to a swamp like green pond. Also, frogs and even a turtle had taken up residence along with water boatmen bugs in the pool. Enough was finally enough, so I ordered and installed a new pool pump, Hayward 700, Superpump, 1hp. I begin the ugly task of removing the growth and other things in the pool, algae/leaves/pine needles/frogs/turtle etc. Then vacuumed to waste and bushed the pool thoroughly. I followed the SLAM process as directed by TFP without deviations. Additionally, I brushed and vacuumed the pool twice each day (AM/PM). After a very short time, the pool turned clear. For me, it was just staying the course and committing to the SLAM process without deviating from the methodology which resulted in a clear pool. Thanks to all the advice/education of the TFP!

Lessons learned: Replace the pump, and get the water flowing as soon as possible. Keep the maintenance going even after swim season.
Boatman:
SLAM:
 
  • Like
Reactions: gregsfc
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.