trichlor vs liquid chlorine and PH

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J

Jonsstihl

Well-known member
Sep 2, 2021
83
Quebec, canada
Hi guys,
I've had a spa for a year now beachcomber 340. using liquid chlorine at first. but had an issue with PH rise all the time even with lower TA. over the winter with reduced use. I got tired of adding chlorine every day so I used the trichlor pucks the spa came with. been using them since the last drain and fill middle of Jan. Now I realized my CYA is way too high over 100 probably 120. now according to the charts I should be adding more pucks to raise the FC but that will just make the CYA worse.
I use a floater and only put one puck in at a time. one puck lasts about 4 days in the floater and then I coast for a few days to let the FC drop a little before adding another puck
I know this is bad but my problem is that the spa has never been so nice. I rarely have to add acid. the water smells nice all the time. with liquid chlorine we sometimes get a waft of unpleasant odours. My CSI index is not too far off target.

we have been using the awesome purge at both first and second fills the only one we skipped was the one in January that was just a drain and fill as fast as possible.

I'm wondering if the fact that we use the spa less often in the winter is partly to blame for the water being "Nicer"

I'm thinking of switching to a saltron mini but kind of worried about the heater crapping out in the middle of winter.
 
Trichlor is acidic and so it will lower pH as it dissolves and releases chlorine. This is why you don’t need to add acid often - the trichlor is keeping the pH and TA down. If you use trichlor, you should be regularly checking pH and TA as low pH will do way more damage to your heater than the salt from using an SWG.

It’s up to you on how you want to sanitize your tub and what’s easiest for you. Just know that as the CYA increases you need to have higher levels of FC (maintain a 7% ratio of FC/CYA) or else you risk the active chlorine levels being too low to keep bacteria in check.

The off odors from liquid chlorine were probably just a consequence of hitting the water with a high load of chlorine and that generated CCs from anything in the water. With a floater you’re adding chlorine but it’s slower and more regulated. Keeping a tub covered all the time will also lead to bad smells as the large covers tend to absorb a lot of funky odors and can develop mold themselves. A tub really needs to be aired out everyday.

Manual additions of chlorine everyday is certainly the biggest pain with the dichlor-then-bleach method. So it’s understandable to look to alternatives.
 
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I have been keeping an eye on TA and PH but PH is fairly steady and I never have to add anything to raise PH when using trichlor. For the TA I usually wait until it hits 40 before raising it back to 70 . but with liquid chlorine I didn't have to do that often. but with trichlor usually every two weeks.

filter cycles 4 hrs a day but I haven't played with those settings since getting the spa. I usually clean the filter once a month but honestly this last drain and refill I haven't cleaned the filter since mid Jan. the water is nice and clear and doesn't smell so I left it alone, and it is not very fun to do when there is snow outside and cold...

nothing in there to absorb oils but it hasn't been a problem. not really any film on the sides.

one thing to note is that we don't like running the air so the PH rises on its own without aeration.

I had the same problem with my pool about constantly adding acid to lower the PH but that seems to have solved itself in the second year.

One question I had was about the PH test not being valid above 10PPM but I have the electronic PH meter from TFS test kits. Is it just the drop test that is invalid?
 
Jonsstihl said:
I have been keeping an eye on TA and PH but PH is fairly steady and I never have to add anything to raise PH when using trichlor. For the TA I usually wait until it hits 40 before raising it back to 70 . but with liquid chlorine I didn't have to do that often. but with trichlor usually every two weeks.
Click to expand...

I'm not too familiar with SWG chemistry differences, but I would think that with liquid chlorine you should never have to do that...

Jonsstihl said:
filter cycles 4 hrs a day but I haven't played with those settings since getting the spa. I usually clean the filter once a month but honestly this last drain and refill I haven't cleaned the filter since mid Jan. the water is nice and clear and doesn't smell so I left it alone, and it is not very fun to do when there is snow outside and cold...
Click to expand...

I know what you mean, but the filters really should be at least rinsed off every month, period adjusted for usage (bather hours, wrinsed off suits...)

Rotating through an extra filter or two is typical

Jonsstihl said:
nothing in there to absorb oils but it hasn't been a problem. not really any film on the sides.

one thing to note is that we don't like running the air so the PH rises on its own without aeration.

I had the same problem with my pool about constantly adding acid to lower the PH but that seems to have solved itself in the second year.

One question I had was about the PH test not being valid above 10PPM but I have the electronic PH meter from TFS test kits. Is it just the drop test that is invalid?
Click to expand...

Borites can help with slowing ph rise, but it sounds like you have some decisions to make. Matt's advice is (always) spot-on
 
I tried borates in the pool the first year and I tried them in the spa as well but didn't really notice a difference in the PH rise.

the spa is always covered so no external debris is getting in. It definitely doesn't get opened every day especially during the winter. I do have extra filters so I rotate them as they are cleaned.
 
Spa's do require work, so the SWG can be quite helpful in that regard. They also tend to outlive break-even so potentially save time and eventually, money too.

I prefer daily dosing at the moment.

I'm surprised the borites didn't make an observable difference. It does with mine. (Not much genuinely surprises me)

Anyway, I'm going to double down on what Matt said, Trichlor is more likely to cause damage than other alternatives. He's a VERY smart fellow...
 
Jonsstihl said:
One question I had was about the PH test not being valid above 10PPM but I have the electronic PH meter from TFS test kits. Is it just the drop test that is invalid?
Click to expand...

Yes, only the drop test.

The phenol red indicator dye turns into chlorphenol red at high FC, which still acts as a pH sensitive dye, but makes the colour transition from yellow to red already at lower pH. At normal pool pH between 7 and 8 chlorphenol red always looks purpely red, therefore you always think your pH is above 8.

Electronic pH meters don't care about the FC level.
 
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Just seeing this-
Trichlor is not recommended for spas due to the fact the hot water can dissolve it very rapidly leading to a low ph or high fc condition which can damage your shell, cover, & equipment.
Best to use dichlor until cya reaches 30ppm then switch to liquid chlorine & or a swg if you can’t be available to maintain fc.
A cya of 90 in a spa is not maintainable & makes it hard to follow the proper
FC/CYA Levels.
Time to purge,drain, & start over following the guide 👇

How do I use Chlorine in my Spa (or pool)?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...
www.troublefreepool.com www.troublefreepool.com
 
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Also, Did you keep adequate fc in the tub afterwards? You aren’t logging cc’s - are you testing for that in your spa?
 
Maybe some residual funkiness trapped under the cover. No matter how well you rinse sometimes the Ahhsome is still in the pipes & may dislodge some more stuff.

It’s a good idea to always leave the cover off 30 minutes or so after dosing to allow cc’s to escape, this also helps with the longevity of your cover.

Just Keep adequate fc & maybe leave the cover off a while to air things out & let the sun help burn off any remaining cc’s (if the tub is outside/exposed to any light).

Keeping track of cc’s is important because persistent cc’s suggest it’s time to purge,drain, & refill.
 
Mine is on the patio so if I’m sitting out there I will just open the lid for a while. In fact, I’m doing that right now 😁
 
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