New spa, perplexed already

[EricJ320]

Let me start off by saying I’ve been living the TFP life for about two years with our pool. I’m all in and love it, even put others on to it. The pool is dialed in, other than some brushing and dropping in MA every so often, it’s fairly, well, trouble free. So thank you all for that.

Now on to my issue. We ordered a new spa, a Master Spa Twilight Series 8.2, last October, and after a nearly 14 month wait it finally arrived this past Tuesday. We filled it, did an Ahhsome purge, drained it, cleaned, refilled, added chemicals to balance it and started using it the next day.

My issue is it’s going through FC at a fairly high rate. I’ve always been one to keep our pool on the high side of the FC window, and I was looking to do the same with the new spa, but it’s been troublesome, for lack of a better term. I read the stickies on this forum to get myself educated and ready for the spa to come. I used dichlor for the initial phase of sanitizing to get the CYA to 30. I was diligently logging my additions to know when I hit 30ppm, which happened yesterday and I was able to confirm it by doing a CYA test, and the dot went invisible just at the 30 line. I’ve now switched over to liquid chlorine, bleach actually at 7.5%. (I have questions about that, but I’ll save that for later to not confuse this post)

During the day I’m having to add LC multiple times to keep the FC above the min for 30 CYA. My CC has never been above 1, and usually goes down to .5 or what looks like lower after I’ve dosed with LC. I’ve gotten the TA down to 50, and have boric acid on the way to get some borates in it, but honestly the ph has stayed fairly constant the last day or two, at 7.4, occasionally and temporarily at 7.6. I suspect it’s giving me 7.6 if I take the sample while the jets are on, and 7.4 when they are not. Admittedly, I may be taking the sample too close to the surface that may be causing those spikes to 7.6, with a return to 7.4. I’ve never added ph up, so I don’t why it would go up other than aeration, but the drop back down to 7.4 is a little strange, but those are my theories as to why.

Each morning it has 0-.5 FC, to which I immediately bring it up to 6ppm or so. Today I went ahead and took it to 11ish ppm and tried to keep it there most of the day to maybe try to kill off whatever could be causing it. I know this isn’t a full slam, and maybe that’s what it needs until it meets the exit criteria, but honestly I’ve never had to slam my pool, so I’m a little new to it.

The spa does have an ozone generator, and I think I read that can consume FC, but other than that I’m not sure what I may need to do. The tub has only been filled for 5 days, and I feel like I’ve been on top of it. Any thoughts or suggestions?

 

[jseyfert3]

Welcome to the hot tub life!

Spas have really high chlorine demands. Lots of bather waste in a small quantity of water. One thing I do is add enough liquid chlorine to take it to SLAM level (so 12 ppm with a CYA of 30) immediately after getting out of the hot tub. This should hold it over till the next morning where you may need to add a bit more. I’d start with this and the report back how that goes.

Also I got a Saltron Mini SWCG and absolutely love it. I still need to add chlorine manually after a soak but then the SWCG takes care of it in-between uses. May be something to put in your list of things to get.

 

[EricJ320]

Thanks for the reply. I definitely knew they were more work, I guess I’m just taken by how much more. From the sounds of it, my experience is rather normal, I’m just not putting enough LC after a soak to counter act the bather deposits and also maintain until later the next day. I’ve read people actually adding LC during a long soak, how is that best done safely? Center of the tub, into the filter compartment? Not at all? And then essentially slam it after. I’ll try that and report back.

You raise a good point on the saltron mini and have looked into, I have the SWG in the pool and I absolutely love it, I’d never have a pool without it. I’ve automated my SWG and Polaris 380 on z wave switches and schedule them through Alexa, and have a VLink for my VS pump, so the pool nearly cares for itself. I’m very interested in simplifying the spa as well. My only hold back has been all the talk of not using a SWG in a spa, and possibly damaging it/voiding the warranty. I suspect that’s just talk, but it had me nervous.

I guess that brings me to my other question. What is with all the negativity over using liquid chlorine/bleach in a spa as well? The manufacturer says no, many “respectable” industry people advise against it, claims of damage to components, damaging O rings, staining the cabinet, shell, or pillows, etc. I get that the TFP method can be controversial, especially to people who have a vested interest in “conventional” sanitation methods, but to some extent isn’t chlorine chlorine? Like I said, I’m all in on the TFP method, but all that had me nervous about switching to LC after dichlor brought the water to 30ppm CYA, but TFP has not let me down yet, so I pressed on. At the end of the day, I have a young daughter with CF, and cleanliness of the water is paramount. I just want to do it well for her (and in turn all of us) and care for the tub at the same time.

Thanks again for the help!

 

[A.O.]

Welcome to the hot tub life!

Spas have really high chlorine demands. Lots of bather waste in a small quantity of water. One thing I do is add enough liquid chlorine to take it to SLAM level (so 12 ppm with a CYA of 30) immediately after getting out of the hot tub. This should hold it over till the next morning where you may need to add a bit more. I’d start with this and the report back how that goes.

Also I got a Saltron Mini SWCG and absolutely love it. I still need to add chlorine manually after a soak but then the SWCG takes care of it in-between uses. May be something to put in your list of things to get.

So how much chlorine do you add to get to that 12ppm level when you get out? I normally add 3 oz of 12.5% chlorine after use and its fine at the next use (2x a day usually). I dont test right as I put chlorine in but normally between uses in the day to keep an eye on it and its usually in that 3 range.

 

[PoolBrews]

Does your spa have an ozonator? Ozonator's heavily impact chlorine usage, and can cause you to think you're running through lots of chlorine. With an ozonator, you only need to keep chlorine at 0.5ppm. I have a Saltron Mini with a 250 gallon hot tub and run it 3 hours per day. Depending on when I check chlorine I either have 0 or 1 ppm. If I check right after the Saltron runs, I have 1-2ppm. If I wait a while, I might get 0.5-0 ppm. Regardless, I know chlorine is going in, and my hot tub is crystal clear.

 

[jseyfert3]

So how much chlorine do you add to get to that 12ppm level when you get out? I normally add 3 oz of 12.5% chlorine after use and its fine at the next use (2x a day usually). I dont test right as I put chlorine in but normally between uses in the day to keep an eye on it and its usually in that 3 range.

PoolMath gives 5.2 oz to add a full 12 ppm of FC. At this point I don't test and more guestimate the amount to add. Past testing has indicated for long soaks the FC will be 0 or almost so after we get out, so for those long soaks I'll add the full 5 oz. For shorter soaks I guestimate it and add a few oz.

You raise a good point on the saltron mini and have looked into, I have the SWG in the pool and I absolutely love it, I’d never have a pool without it. I’ve automated my SWG and Polaris 380 on z wave switches and schedule them through Alexa, and have a VLink for my VS pump, so the pool nearly cares for itself. I’m very interested in simplifying the spa as well. My only hold back has been all the talk of not using a SWG in a spa, and possibly damaging it/voiding the warranty. I suspect that’s just talk, but it had me nervous.

The only damage I could potentially see is the seat/wall next to the hang-over SWCG eventually getting damaged from the higher local concentrations of FC, but I haven't seen that on my spa in a year and a half. I suspect my worry is misplaced, given the spa cycles on the low speed pump every 15 minutes for a minute or two to check temps, plus filter and ozone cycles and heating times.

I have a used tub so no concern with warranties, but I can tell you I will go with a SWCG again if we ever buy a new spa.

I guess that brings me to my other question. What is with all the negativity over using liquid chlorine/bleach in a spa as well? The manufacturer says no, many “respectable” industry people advise against it, claims of damage to components, damaging O rings, staining the cabinet, shell, or pillows, etc. I get that the TFP method can be controversial, especially to people who have a vested interest in “conventional” sanitation methods, but to some extent isn’t chlorine chlorine? Like I said, I’m all in on the TFP method, but all that had me nervous about switching to LC after dichlor brought the water to 30ppm CYA, but TFP has not let me down yet, so I pressed on. At the end of the day, I have a young daughter with CF, and cleanliness of the water is paramount. I just want to do it well for her (and in turn all of us) and care for the tub at the same time.

I have no clue where this comes from. Yes, while the different types add different things in addition to chlorine (dichlor and trichlor add FC & CYA and are both acidic, for example), the actual chlorine part is exactly the same. One type will not magically cause damage while the another type won't when you add the appropriate amount to target the appropriate FC level.

 

[jimmythegreek]

With ozone don't sweat the fc #. Dose it after use on the heavier side and do so every few days. I go a week sometimes w no fc added. If I do go that long I dose lightly earlier that day then use and hit it again. Don't treat it so much like a pool

 

[EricJ320]

With ozone don't sweat the fc #. Dose it after use on the heavier side and do so every few days. I go a week sometimes w no fc added. If I do go that long I dose lightly earlier that day then use and hit it again. Don't treat it so much like a pool

That’s good info. I’m just concerned by what metric I’d use to make sure the tub is being properly sanitized? I am seeing this is very different from a pool, but I like having something to look to for making sure a proper level of sanitation is present. Is it CC levels, the appearance of the water? Or is it just sticking to a proper dosing schedule that I would assume it’s clean water? That just seems somewhat subjective to the amount of usage and interval of dosage.

 

[5tan]

I’m just concerned by what metric I’d use to make sure the tub is being properly sanitized?

The metrics I use to make sure my spa is being properly sanitized are Free Chlorine and Chlorine Demand (CD), noting that the lower your CYA level and the lower your pH, the more effective the chlorine is at sanitization.

On a new fill, I add enough dichlor (3 x 20g dichlor tabs over a few days) to reach 18ppm CYA, and with all the splashout from lots of use, I add new water without adding any more dichlor, so my real CYA level is less than 18. I keep my pH in the 7.4-7.6 range, and shoot for 7.4 when adding acid, for 2 reasons: (1) higher chlorine effectiveness, (2) less frequent addition of acid due to normal pH rise caused by jets aerating the water.

After a heavy bather load session, I add enough liquid pool chlorine to reach 10-12ppm FC per PoolMath, or even more if I know the bather load was extra heavy (lots of people + lots of hours). Then I check the chlorine demand 12-24 hours later. If my FC dropped from 12 to 1-3 in 24 hours, CD is high, and I'll add more chlorine per PoolMath to hit 12. In another 12-24 hours, the FC drop per hour should be less than the previous time, and I'll top the FC up to 10-12 again. Repeat until CD is minimized. If I know when I'll be jumping in next, then I adjust my dosage and timing such that FC is under 5 when I get in, and will force my ozonator to run for hours if I need to significantly increase CD.

If you have an ozonator that always runs during heating cycles, filtration cycles, and temperature checks, expect high CD. You can reduce your CD and verify "natural" FC decay by disabling your filtration and turning your heater low, or eliminate 100% of ozonator-caused CD by unplugging the ozonator.

Ozone alone will not keep your spa sanitized. Ozone does not provide any residual effect and doesn't stay in the water whatsoever - any water not immediately in the path of the ozone gas will not be sanitized. The ozone gas is only effective for the water it immediately touches. Any water not mixed in with the ozone gas bubbles will not be sanitized by the ozone - the water needs to thoroughly mix with the ozone gas just to sanitize that specific "batch" of water.

A primary sanitizer like chlorine is required to be touching every surface at all times, and circulating well enough to eliminate localized depletion of chlorine. It's very good practice to never let FC drop below 3ppm and to never let pH go above 7.8, regardless of presence of ozonator or the products you use. With FC below 3ppm, unwanted organics can grow in the piping, jets, various surfaces, etc.

Ozone, minerals (e.g. Nature2), and enzymes only give the chlorine a tiny bit of extra help - none alone can replace chlorine.

Now, if you performed a thorough biofilm removal regimen (e.g. Ahhsome purge) shortly prior to this fill, and sustained the specified FC shock ppm for several days to kill off 100% of all organic materials everywhere inside the spa, plumbing, headrests, shell, etc, then your water can stay clean for weeks, regardless if you have an ozonator or not. Your water will even stay sanitized when FC naturally decays to zero, assuming your cover is 100% airtight and no contaminants, pollen, dust, spiders, etc are being introduced.

 

[jimmythegreek]

I use the pour method. Light pour for light loads and heavy for heavy loads. I use about 3oz for like light and 6 to even 10oz for heavy. Kind of like a slam of sorts. That high dose disinfects and ozone clears it all out anyways. Obviously test as ph is crucial but don't sweat fc so much. If you hit or exceed the fc ratio for your cya you are good to go. The water clarity is a good visual. Nothing wrong with dosing lighter the next day either for reassurance

 

[RDspaguy]

Ozone is a strong oxidizer, and will burn off free and combined chlorine. Think of it as a shock, not a sanitizer. But a shock so strong it destroys chlorine. Raise your chlorine after use to sanitize and let the ozone get rid of the cc and excess fc.
A constant residual is not needed in a covered spa, as it is in a pool, because new contaminants are not introduced with the cover closed (unless it's old and leaky and it rains). On a 24/7 injection system, the entire volume of the spa is moved through the injection pipe (turnover) every hour or so, and they say that 5 turnovers will get 99% of the water, and therefore contaminants in the water, in contact with ozone. This leaves little chance for nasties to grow, even with .5ppm fc. On a timed system it get's alot harder to determine turnover, as the main pump is moving only some of the water through the ozone pipe.
You can unplug your ozone from the control board and test the theory if you like. If your chlorine, both free and combined, stick around, it's the ozone getting rid of it.
Another indicator is 0cc, as the ozone burns it off. If the chlorine is used up during sanitation (chlorine demand) it will raise the cc, just like a pool, and require a chemical shock (or salt cell or uv) to remove it. If you add fc, but don't get a resulting fc or cc the next day, it's the ozone.
Ozone is not recognized as a sanitizer in a spa because the treated water is returned to an untreated tub with no residual. It destroys contaminants better than chlorine, but there is a risk to using it without a sanitizer. That said, I have never had a customer have any issues with a low chlorine/ozone system as long as the ozone is working. Since the ozone will die sooner or later, and the only way you will know is the sudden buildup of cc and cloudy water, it is a good idea to use chlorine even if it seems that you don't need it.
It has been many years since any manufacturer has recommended ozone as a primary sanitizer, but some people still use it the way it was sold to them in 1998, and recommend it to others. This has caused alot of confusion regarding ozone, even at the pool/spa store, where the new guy is often given old information by old guys like me. Since I used a low chlorine/ozone system for well over a decade, and recommended it to my customers, without issues, it took some convincing to get me to believe that there is a risk at all.

 

[EricJ320]

Ozone is a strong oxidizer, and will burn off free and combined chlorine. Think of it as a shock, not a sanitizer. But a shock so strong it destroys chlorine. Raise your chlorine after use to sanitize and let the ozone get rid of the cc and excess fc.
A constant residual is not needed in a covered spa, as it is in a pool, because new contaminants are not introduced with the cover closed (unless it's old and leaky and it rains). On a 24/7 injection system, the entire volume of the spa is moved through the injection pipe (turnover) every hour or so, and they say that 5 turnovers will get 99% of the water, and therefore contaminants in the water, in contact with ozone. This leaves little chance for nasties to grow, even with .5ppm fc. On a timed system it get's alot harder to determine turnover, as the main pump is moving only some of the water through the ozone pipe.
You can unplug your ozone from the control board and test the theory if you like. If your chlorine, both free and combined, stick around, it's the ozone getting rid of it.
Another indicator is 0cc, as the ozone burns it off. If the chlorine is used up during sanitation (chlorine demand) it will raise the cc, just like a pool, and require a chemical shock (or salt cell or uv) to remove it. If you add fc, but don't get a resulting fc or cc the next day, it's the ozone.
Ozone is not recognized as a sanitizer in a spa because the treated water is returned to an untreated tub with no residual. It destroys contaminants better than chlorine, but there is a risk to using it without a sanitizer. That said, I have never had a customer have any issues with a low chlorine/ozone system as long as the ozone is working. Since the ozone will die sooner or later, and the only way you will know is the sudden buildup of cc and cloudy water, it is a good idea to use chlorine even if it seems that you don't need it.
It has been many years since any manufacturer has recommended ozone as a primary sanitizer, but some people still use it the way it was sold to them in 1998, and recommend it to others. This has caused alot of confusion regarding ozone, even at the pool/spa store, where the new guy is often given old information by old guys like me. Since I used a low chlorine/ozone system for well over a decade, and recommended it to my customers, without issues, it took some convincing to get me to believe that there is a risk at all.

Thanks for that awesome description. It’s very helpful to understand how the ozone/chlorine combination works and figuring out how to keep our tub balanced and safely sanitized.

 

[phonedave]

I use the pour method. Light pour for light loads and heavy for heavy loads. I use about 3oz for like light and 6 to even 10oz for heavy. Kind of like a slam of sorts. That high dose disinfects and ozone clears it all out anyways. Obviously test as ph is crucial but don't sweat fc so much. If you hit or exceed the fc ratio for your cya you are good to go. The water clarity is a good visual. Nothing wrong with dosing lighter the next day either for reassurance

I stopped with the exact measuring as well. I still test pH and FC (and CC), but my dosing is usually a "small splash" in the AM, and a "bigger splash" whenever we get out after using the tub.

I tend to estimate on the high side, so every so often I test and I say to myself "hmmm. that really does not need a small splash this fine morning" and then I go about my day.

 

[A.O.]

I measure every time, takes about 2 seconds.

 

[EricJ320]

I measure every time, takes about 2 seconds.

I just recently bought a Tip N Measure 64 oz bottle for bleach that has made it very easy to add FC. It’s a green bottle, I was hoping it wouldn’t degrade from light exposure, but it’s definitely more transparent than a white bleach bottle. Do you notice any degradation of the chlorine in your bottle?

 

[A.O.]

I just recently bought a Tip N Measure 64 oz bottle for bleach that has made it very easy to add FC. It’s a green bottle, I was hoping it wouldn’t degrade from light exposure, but it’s definitely more transparent than a white bleach bottle. Do you notice any degradation of the chlorine in your bottle?

None at all, it stays inside all the time.
In my little "cabana" the two doors on the left... left door is a bath, the right one is my mechanicals room with all the pool equipment and chemicals.

 

[phonedave]

I measure every time, takes about 2 seconds.

It makes it slightly easier to dose, but not really more accurate. The first major source of error is the volume of water in your tub. You are guessing. It could be off by 10%.

Most significant digit. If one of your variables has 10% error bars on it, your could measure your bleach down to the mil and it does not make a difference.

 

[A.O.]

It makes it slightly easier to dose, but not really more accurate. The first major source of error is the volume of water in your tub. You are guessing. It could be off by 10%.

Most significant digit. If one of your variables has 10% error bars on it, your could measure your bleach down to the mil and it does not make a difference.

Well it does not need to be more accurate now does it? I put it in the tub, and if I test it , it is right where it needs to be... no reason to over think things!!

 

[jseyfert3]

It makes it slightly easier to dose, but not really more accurate. The first major source of error is the volume of water in your tub. You are guessing. It could be off by 10%.

Most significant digit. If one of your variables has 10% error bars on it, your could measure your bleach down to the mil and it does not make a difference.

A 10% error on the water is way less error than a "small splash" or a "large splash". And if off by 10% on the water volume then if you do a couple tests with accurate chemical additions you'll start to note you consistantly over or under-shoot the target. For example if you weigh out dichlor on a gram scale and measure FC before and after, and you are always over or under shooting your target, then your water volume is off. I used this "chemical method" to adjust my "450 gallon" hot tub down to 420 gallons.

For a hot tub an exact hot tub volume is actually pretty easy. Just note your water meter value, fill the tub while not using any other water, then note your water meter again once you finish filling.

 

[A.O.]

For a hot tub an exact hot tub volume is actually pretty easy. Just note your water meter value, fill the tub while not using any other water, then note your water meter again once you finish filling.

That only works if you have a water meter, not everyone has one. My well does not.