Trichlor and Liquid Chlorine experiment!?

Dtkokay

Well-known member
Dec 31, 2019
263
Houston, Texas
With trichlor only, it is very difficult to impossible to maintain your FC in the target range of the FC/CYA Chart.

Also be sure you only get plain trichlor tablets. You do not want to add copper to your pool.
Agree 100%. I was doing the math comparison purely for my own academic curiosity.

For background, I started off with trichlor in my new pool at the beginning because I had to wait 30 days before turning on the SWCG, trichlor was convenient and added CYA, and liquid chlorine was incredibly hard to find at the time. I tried my SWCG after the 30 days, but it has been having intermittent issues, so I continued with the trichlor until my CYA hit 60. That was around a week ago, at which point I switched to liquid chlorine while the PB sorts out the issue with my SWCG.
 

Dtkokay

Well-known member
Dec 31, 2019
263
Houston, Texas
With trichlor only, it is very difficult to impossible to maintain your FC in the target range of the FC/CYA Chart....
On a related note, I was talking to one of my neighbors about our pools, and he said his CYA was 120 and that he keeps his FC in the 1-3 range for warranty purposes. Then yesterday I saw that he was draining his pool. I haven't had a chance to talk to him yet, but I'm guessing he has algae.
 

mariane

LifeTime Supporter
May 8, 2012
1,030
Southeast Michigan
Depending on the size of the tabs of trichlor, I could see it would make a difference. ie. tabs vs. sticks vs. powder
Do you use a scale to weigh how many tabs = 1 lb? It's easy to see 1 lb with powder but not as easy with tabs or sticks.
 

DanF

Silver Supporter
Mar 17, 2019
152
Chandler, AZ
Depending on the size of the tabs of trichlor, I could see it would make a difference. ie. tabs vs. sticks vs. powder
Do you use a scale to weigh how many tabs = 1 lb? It's easy to see 1 lb with powder but not as easy with tabs or sticks.
I believe a 3" trichlor tab is 8 oz, but now you got me wondering. I'm gonna weigh one here shortly.
 

Chasarms

Silver Supporter
May 8, 2020
269
Dardenne Prairie, MO
Too many cannonballs? :drown:

Could be. I’m more like a napoleonic heavy mortar.

I started fresh fill this spring. I added four pounds, which PM says gets me to 30. I tested at 20 but attributed it to the fact that I used the generic CYA that the PB put in the start up kit last year.

A few weeks in, I bought four pounds and added two. Tested at 30. Couple of weeks ago added two more pounds trying to push it up a little. Tested at 40.

According to PM, eight lbs should put me at 60, but again the first batch of CYA was suspect. That said, I all but certain I’m losing CYA at a modest rate.

I’ll test again in a few weeks. I bought four lbs yesterday to have on hand, just in case. I’m betting I have add again this year to hold 40.
 

calinb

Well-known member
Jul 18, 2018
116
N. Central, ID
CYA degrades more rapidly at high water temperatures. It is more of a problem in AZ & TX then NJ.

Degradation of Cyanuric Acid (CYA)
Yeah--I think mknauss has reported somewhere how much CYA he loses in sunny Laughlin, NV. It's not completely insignificant, as I recall. The first two seasons that I opened my pool here in Idaho, I had the opposite problem. Winter consumed ALL my CYA. This season was different--maybe because the winter wasn't as long or as harsh or maybe because my pool chlorine chemistry is still borked from the sulfamic acid/Jack's #2 treatment I did late last season.

I use whatever I need for the desired chemistry. LC is the most expensive form of Cl for me right now. Trichlor is the cheapest source of both Cl and CYA (It's like buying stabilizer super cheap and getting the Cl for free.) In 50 lb online purchases, trichlor pucks might even be cheaper than SWG electricity and cell replacement reserves. For SLAMming this year, I used two mesh bags with 10lbs each of trichlor pucks (positioned right in front of the return jets) hung from 1x2 lumber on paracord. SLAM Cl levels were achieved literally overnight (CYA was initially 30 and I needed higher in preparation for new SWG).

When I first got this house and pool, I started a SLAM with trichlor pucks after pulverizing and dissolving them in 5 gal. buckets of water. It's a lot of work with nasty stuff though. (Don't breath the dust!) Hanging mesh bags in front of jets is much easier and safer, if CYA is low enough to warrant the use of trichlor at all.

Once my CYA is where I want it, I'll use cal-hypo for a SLAM, assuming I can handle the CH increase, which is usually embraced due to CH splash-out and filter backwashing losses. LC has increased in price so much in this panic-demic year that even cal-hypo is a cheaper Cl source than LC but, after I got my CYA and CH where I wanted them, I pushed the button and powered-on my new SWG only about two weeks ago. :)
 
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