Can I just use a combination of liquid chlorine and trichlor???

nybrian

Member
Jul 23, 2020
5
Phoenix
It has become obvious to me that solely using trichlor and stabilized shock raises my CYA way too high. Is there a problem using a little of both? Cutting my 3" tab usage down by 50% and making up the rest with liquid? That seems to be the easiest way to keep enough CYA in the pool without reaching astronomical numbers...
 

Yev

Well-known member
Jul 29, 2014
544
Independence, KY
Doubtful on a regular basis. CYA really never goes away without replacing water. For someone in the midwest who gets lots of rain (~43" per year) I have to add CYA every season to get things just right since the rain dilutes thing out so much. But being in a low rain area like Phoenix, you wont get that benefit. Now putting in a tab if you are away for a couple of days might, and I emphasize might be OK, from time to time.

as @mknauss said, we would need to see more test results, and details about your pool. But as a general rule, in the desert, most likely tabs are only for vacations, not daily usage.
 

sbcpool

Well-known member
Mar 10, 2015
584
Upland, CA
Doubtful on a regular basis. CYA really never goes away without replacing water.
It disappears pretty fast in water with 0 FC and low dissolved oxygen. I suspect those of us who routinely see CYA disappear in the winter months have a combination of 0 FC and short pump run times. It's not something that can be done with water temperatures over 60°F or so. The algae would be insane, especially after the CYA was converted to ammonia.

This is basically irrelevant to OP's question unless an entire season of using trichlor for 50% of his chlorine needs will keep CYA below sane limits.
 

nybrian

Member
Jul 23, 2020
5
Phoenix
I don't have a tester that works for me---all those colors look the same to my colorblind eyes. I go to Leslie's and this is where I am at:
FC: 1.53
TC: 1.66
pH: 8.0
Total Alk: 82
Calcium Hardness: 408
Cyanuric Acid: 121
Copper: 0.3
Phosphates: 0
TDS: 1600

I was told to drain the pool in the winter, which I will do. Until then, I want to hobble thru to the end of swim season and not destroy my pool.
 

sbcpool

Well-known member
Mar 10, 2015
584
Upland, CA
Ouch. With that level of CYA you don't want to add any more. That level requires a minimum FC of 10 and a target FC around 16 - 18 for proper sanitation and algae control. If you bought 10% chlorine from Home Depot, you'd need to add about two gallons to raise it to that point and then see how much you're losing to calculate how much is needed every day.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,930
San Dimas, CA (LA County)
IF (huge if) those test results are accurate, the answer to your question is no.

If CYA is already at 120, your minimum chlorine level should never dip below 9, with a target of 12 or 13, depending on how much you lose every day. If you keep feeding it pucks, that 120 is going to climb, and so will the minimum FC required. It is possible to maintain a pool with really high CYA; I've done it. I don't recommend it and it's not easy and it pretty much demands that you do your own testing every day. And the pH will be at best questionable. But trying to do it while the CYA is climbing? Forget it. You might as well just completely stop adding anything to the pool because algae is almost a given.
 
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Jeff J.

Well-known member
Aug 6, 2019
221
Staten Island NY
I don't have a tester that works for me---all those colors look the same to my colorblind eyes. I go to Leslie's and this is where I am at:
FC: 1.53
TC: 1.66
pH: 8.0
Total Alk: 82
Calcium Hardness: 408
Cyanuric Acid: 121
Copper: 0.3
Phosphates: 0
TDS: 1600

I was told to drain the pool in the winter, which I will do. Until then, I want to hobble thru to the end of swim season and not destroy my pool.
Unfortunately, you can't rely on those results. If you can't use a TF-100 or K2006-c due to your colorblindness, you could pick up a Lamotte Color-Q, which is digital. It's not as good as the other ones, from what I understand, but better than test strips or pool store testing. You could also order the CYA test from TFTestkits.Net, since it doesn't require color distinctions.
 

HermanTX

Gold Supporter
May 20, 2020
647
Katy TX
It has become obvious to me that solely using trichlor and stabilized shock raises my CYA way too high. Is there a problem using a little of both? Cutting my 3" tab usage down by 50% and making up the rest with liquid? That seems to be the easiest way to keep enough CYA in the pool without reaching astronomical numbers...
Your CYA is quite high and as noted by others you must increase your FC level. To stop CYA increasing, stop using pucks completely and use only liquid chlorine. This will at least minimize how much water you may need to drain. You must test daily using the DPD powder to get an accurate FC reading. It is not so much color related as you are looking for it to turn clear. Instructions are with the test kit. Be prepared to add liquid chlorine daily. I have my CYA at 90 and have been able to keep it in check going the 100% liquid chlorine. If I go out of town for a weekend, I add 1 puck to my floater as a back up. Now I plan to do a proper drain in the Fall to get back to a more stable system but it works for me now while we are using the pool daily and keeping the FC at proper level per the CYA/FC chart.
 

nybrian

Member
Jul 23, 2020
5
Phoenix
Thank you all; great information. I have watched the CYA slowly creep up from the 70's to the 120's. It's brutal that every "expert" I talked to just says "keep adding more pucks". Anyhow, monsoon season is starting and hopefully we can get a few inches of rain to help the cause.
 

sbcpool

Well-known member
Mar 10, 2015
584
Upland, CA
I am colorblind as well. The only test that I cannot perform on my own is the calcium hardness test. For my eyes it's already blue from the start :LOL: Everything else is no problem though. Don't be scared off unless you know for certain that this particular test doesn't work for you. The CYA and chlorine test will work even for someone with black and white vision.
 
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Yev

Well-known member
Jul 29, 2014
544
Independence, KY
I don't have a tester that works for me---all those colors look the same to my colorblind eyes.
Someone else here might weigh in on this, but I would think that the CYA test can be done by a color blind person. All you are seeing a black dot that will transition to not being visible. I think that this is the least accurate test you can have done by a store, so maybe (if others agree) you can do this on your own, and let the store do the others.


Anyhow, monsoon season is starting and hopefully we can get a few inches of rain to help the cause.
I think my math is correct. If you are are expecting a big rain, like the next day, drain your pool down a bit, and have the rain fill it back to the normal level. So if you expect 1' of rain, pre-drain 1' before hand.

This will actually perform better than letting the rain come in to mix in with full level, and then pumping some out if you are overfull.
 

Cwiggs

Well-known member
Aug 31, 2019
118
Phoenix, AZ
I live in the Phoenix area and I primarily use liquid chlorine, however every few months I do throw in some trichlor tablets to bring the CYA up.

Like others have said, it's fine to use trichlor tablets as long as you know what your chemicals are at and what the stuff you are putting in is going to do.

If you aren't too far from me I can swing by and help you test your pool, I can bring my tf-100 kit. Just send me a DM and we can sync up.
 
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nybrian

Member
Jul 23, 2020
5
Phoenix
Thank you all for getting me on the right path. My first issue was that my "awesome" pool builder assured me that after it was built they would have someone out to show me how to operate the pool. The guy really seemed annoyed at having to come out and flat out told me the only things I need to test are chlorine and PH. So I never did touch the CYA tester, and boom, now I can at least look for the black dot. And all I know is I am over 100 :(

I think I will limp along for the next 10 weeks, buying ridiculous quantities of liquid chlorine, and then drain the pool and start fresh knowing a lot more than I knew 54 weeks ago when I first filled the pool.

Again, thank you all!!!
 
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Yev

Well-known member
Jul 29, 2014
544
Independence, KY
You may seriously want to consider going ahead and getting a SWG. With that, in phoenix, your CYA should be 70, maybe 80, so maybe you would not need to drain the whole pool.

One thing that you might want to try, and the accuracy when you do this is not perfect, but make up a gallon of test water. Take 50% from your pool, and 50% from your tap. Mix them together. Then perform a CYA test on the mixed water. Your result will actually be 2x due to the dilution. Now you might ask, why? So if with this dilution, your CYA tests about 70, then this tell you that your actually CYA is 140. You can drain half the water out, refill, and get back to a real CYA of 70, which is perfect if you have a SWG. But when you do this, if your CYA tests at 100 diluted, that means your CYA is 200+ without the dilution, and at that point, complete drain and refill is probably the best way to go.

Unfortunately your story of your PB and "Pool School" is way too common of a story. It is a necessary evil that the PBs have to do, but dont want to do. They look at it as a half day of work lost, generating no income. PBs work their butt off building pools, they dont necessarily learn about new technologies, advanced techniques, etc. They learn something to start with, its good enough to get teh job done, and never try to get better. Now of course, this is a over generalized stereotype, but it is way to common to hear the exact story.