Need to add liquid chlorine when using SmarterSpa SWG?

[DrNinjaman]

Moved from here.
Hi, first post on the forum, I'm going to be installing a Smarterspa on my 550 gal Artesian spa in a week or so, and I've been reading up on all the related threads on here. One question I have, everyone seems to be suggesting putting a half a cup of bleach in the tub after use to keep the FC level adequate, but isn't that what the boost button is for on the SWCG? I'm not saying it's a bad idea and I understand that the SWCG is slower at bringing the FC up, but it does seem kind of silly to have this expensive equipment that you still have to supplement most of the time.

 

[Mdragger88]

Most people do this to -
1) get a quick boost as time + low fc in a hot tub is not good & nasties will grow
2) preserve the life of their cell - it is only good for a finite amount of fc production in its life before it must be replaced & they’re not cheap
I occasionally just turn mine back on vs dosing w/ bleach depending upon the bather load & length of my soak especially if i know my fc hasn’t dropped too low.

 

[duganderson]

Some people don't add chlorine after use. I generally do just to make sure my FC never drops to zero. I bought a Bettix bottle to dispense the chlorine after use which makes it super easy. After using the tub, I just add about one oz of 12.5% chlorine for every 20 minutes of use. So if there were three people in the tub for 40 minutes total, I would add 6 oz of chlorine. This should cover the chlorine demands of use since each hour of use is estimated to use about 7 PPM of FC.

 

[DrNinjaman]

7ppm per person per hour? Does that depend on the size of the tub? That seems like a lot given that you aren't supposed to keep the water at more than 6 ppm for use, right? So anytime I've got say 6 people in the tub, the water is tapped out before the first cycle of the jets? Yikes!

 

[Newdude]

7ppm per person per hour? Does that depend on the size of the tub? That seems like a lot given that you aren't supposed to keep the water at more than 6 ppm for use, right? So anytime I've got say 6 people in the tub, the water is tapped out before the first cycle of the jets? Yikes!

Make no mistake. You are making people soup.
6 people in a 500 gallon tub is the same as 420 people in my 35k pool, and the swimmers aren’t sweating / exfoliating at 104 degrees. So yeah. Ick.

Pay close attention at first to your FC demand and adjust as necessary. You should be able to get a baseline pretty quickly per person about how much residual shampoo / laundry det / sweat / body oils / etc (the icky list goes on and on and on) you are needing sanitized.

 

[duganderson]

7ppm per person per hour? Does that depend on the size of the tub? That seems like a lot given that you aren't supposed to keep the water at more than 6 ppm for use, right? So anytime I've got say 6 people in the tub, the water is tapped out before the first cycle of the jets? Yikes!

Good Morning DrNinjaman.....It should not depend too much on the size of the tub but the cleanliness of the people and their swimming suits and other factors.

I have seen the 7 PPM per person per hour stat a few times on this site but it seems accurate in my experience.

If you have 4 people in the tub for 1 hour, it would take a LONG time (depdending on your settings) for your SmarterSpa or any other Chlorine generator to make enough FC to catch up with the created demand. This is why I tend to recommend adding chlorine after use unless it's just one person for a 20 minute soak or less. I, however, keep my FC in the low range (1-3 PPM) so adding chlorine after for me is a little more important than if you run your tub at higher FC.

Initially, I agreed with your perspective that it seems weird to buy a SWCG but still add chlorine after use. I, however, have come to realize the convenience of a SWCG for me. For me, my SWCG keeps my tub very stable and in the range of FC that I want with minimal effort. This is especially nice if I am not using it consistently, go on a trip, etc. The only thing I really need to manage on a consistent basis is adding bleach after use which literally takes me about 10 seconds and is WAY worth the effort. Also, I check the PH weekly once it is stable but it tends to stay very stable if I run my Alakalinity at 50-60 and add 50 PPM borates when I fill my hot tub.

 

[DrNinjaman]

Duly noted. Adding a quarter-half cup of bleach is easy enough after a party or whatever.

 

[Newdude]

I had no problems tossing in some ‘after’ chems. It was the week or two in between uses when I was otherwise busy that got neglected. Then I’d have to test, shock, mix and wait, test again, then finally get to use.

Once you are dialed in, your SWG will shine and keep everything ready to go for next time, whether it’s tomorrow or 2 weeks from now. It’s worth it’s weight in gold for that alone.

 

[DrNinjaman]

Yeah, I'm still figuring out where to put the zero point and power level. I also have a bit too much salt in the tub, so I'm probably going to have to dump some and refill to bring it down, or it will just keep climbing every time I add bleach until the SWG stops working.

 

[duganderson]

In case this helps for a potential reference point, I have a 400 g. tub. I use 25 for my zero point and power setting 3 (runs 2 hours) which keeps my tub about 1.2—3.4 FC. You're tub is bigger and all tubs are different. I'm, however, guessing you'd want a power setting of 4 (to run 3 hours). Good luck and keep us updated!

 

[DrNinjaman]

In case this helps for a potential reference point, I have a 400 g. tub. I use 25 for my zero point and power setting 3 (runs 2 hours) which keeps my tub about 1.2—3.4 FC. You're tub is bigger and all tubs are different. I'm, however, guessing you'd want a power setting of 4 (to run 3 hours). Good luck and keep us updated!

That is helpful. I did just observe the SWG turn on right after I measured the FC at 2.0 ppm, and it was set to a zero point of 25, so I'm going to bump it down to 20 and see what that gets me. I'd like it to kick in around 1.5ish. The manual said my sized tub should be set to power level 7, or 6 hours, so I'll see what that does once I'm done shocking the thing to get the CC down to zero.

 

[duganderson]

Sounds like you're on track to getting it dialed in.

 

[DrNinjaman]

Sounds like you're on track to getting it dialed in.

Yeah, maybe. We haven't used the tub this week because I was out of town for work. So it's been sitting with the SWG on autopilot at the settings I left it at, power level 4 and zeropoint 20. I checked the FC last night for the first time in about a week, and it was at 7.8! Also, different issue, the combined chlorine continues to report something going on with 0.4 ppm. That is down from 0.6 last week, but I'm still wondering why it's not 0 since it's been sitting idle with apparently sky high chlorine levels for ages. CYA is about 20ppm. Probably a little less since I dumped about 5% of the water and refilled when the salt was too high.
I'm wondering about how accurate the chlorine level sensor is at this point. Today, I opened up the tub to show the electrician that ran the power cord through the wall, and after I lifted the cell out of the water and dropped it back in, it turned on! Again, the water was at 7.8ppm FC last night. I am skeptical that it dropped 6 ppm overnight with nobody using it. I was not able to check this morning to confirm. If it did, I should probably do another purge with some Ahh-some again. However, I wonder if taking it out and dropping it back in can generate a false reading?
Figuring out the level at which it turns on is definitely going to be the trickiest part of setting this up. Maybe I'll make myself a test solution in a bucket and just add bleach until it triggers.

 

[Mdragger88]

The cc’s are from it being closed up for a week - they haven’t been able to escape.
A little breather in the sun with the cover off should help. .4 cc is no cause for alarm

 

[DrNinjaman]

The cc’s are from it being closed up for a week - they haven’t been able to escape.
A little breather in the sun with the cover off should help. .4 cc is no cause for alarm

I was kind of wondering about that. Thanks for confirming.

 

[DrNinjaman]

Well, it seems to be working correctly now, used the tub last night and this morning the cell turned on. Checked the FC as soon as I noticed it and it was at 1.6ppm. After the cycle finished, it was 2.4ppm. I bumped up the power level to get it closer to 3ppm at the end. I'm assuming the lowest FC was 1.6, but it may have been lower, I don't know how long it was running before I checked. I'll watch for the next time it turns on and check when it's done. Gradually getting it dialed in. I am going to need to order some more chlorine test juice though. All those high readings have eaten considerably into my supply.

 

[DrNinjaman]

Stroke of luck, the cell turned on while we were using it tonight, so I got a perfectly timed sample. FC was 1.2ppm. What do you folks think? Is that good, or do I want to tick the set point up a notch or two? I added a dash of dichlor to offset what we used up right away and also to add a little CYA to bring it up to 20 ppm. I'll check the chlorine after the cell finishes running to get the amount it boosts it in one cycle. Then I'll offset by the amount of dichlor that I added so I can figure what just the cell contributes.
It's indicating that the salt is high right now, and the test kit says I'm at 2200ppm salt, which is a bit high for this cell. I did have question about that though, does the salt concentration affect the rate at which it produces Cl? The current increases with increased salt, so that kind of makes me think it produces Cl at a greater rate. Is that true? If I drain and refill to drop the concentration is that going to throw off my calibration points?

 

[Mdragger88]

I would kick it up a dab - under 2ppm is a no go Around 3 or so would be a sweet spot for the start of a soak then setting it to kick on before it gets below 2 - provided u keep cya @ 20ppm. Up 10 ppm fc is totally fine so don’t sweat it if it gets a little high. A 2 person bather load can put a pretty good hit on fc so 2ppm at the beginning of a soak is in the danger zone as it takes a little while for the swg to catch up. But i bet w/ your larger tub 3ppm would be fine. Obviously if your cya increases your set point needs to increase as well. *Always follow theFC/CYA Levels*
I prefer to err on the side of caution. Bacteria bad .. fc good
If u go away you could always lower the set point a dab to prevent over chlorination while u r away.

 

[wireform]

There's no reason to keep the FC at bare minimum. All your doing is skirting with danger of nasties taking over. You'd be better off running the FC a bit hot as it would make very little difference to bathers using the tub. One other suggestion would be to add the liquid chlorine before the soak so by the time the people are out there would still be active FC left over and you'd never be in danger that way.

 

[Dirrby]

The instructions for the smarter spa have you adjust the zero point so the cell turns on at 0 ppm FC. If you are setting it to kick on sooner you wont need as long run time as they suggest because you are not starting from 0. As duganderson suggested try using 4, or even 3 as the power level. For reference, I have a megachlor which i believe uses the same cell and run it for 1 hour per day in an 800 gallon tub and my FC has been steady at 3.5 ppm without manually dosing on top of what it generates.