Questions in hindsight from a new owner

mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
Hi. Thanks to everyone here who has taken the time to help out, over and over, week after week. It's truly a tremendous site.

I've been testing my water and logging it, and have converted to a Saltron swg. But I've got a lot of questions still as I read so many different things on this site. I apologize for the complexity of this post in advance, I write walls of text.

I have a 425g bullfrog tub that is at 101deg. I have been able to keep my pH at 7.4-7.5 sitting and 7.7 after a couple hours use. My CH has been 240 every time I test and the TA is at 40-50 at my current pH levels. These have been very steady after testing multiple times a day.

My salt level has also been static at 2400ppm. Assuming my 30ppm borate and 40ppm CYA have not changed as I've only topped off some fresh water once and only an inch.

I have read here that 20-30 CYA is plenty, yet the FC to CYA conversion shows a SWCG to be 60CYA minimum. What would the consensus be then on a mostly covered outdoor spa be?
Also on borates, I read 30 to 50 but is there truly an ideal?
Does salt water cause either of these to have an optimum?

Bearing in mind that my tub is under UV filtering and covered most of the day, should my Ozone be turned on to help with the CC? I have been struggling with the CC. I have read 0.3-0.5 is the maximum and to shock if above that. Mine has been 1 to 1.5 usually and a few times at 2CC. I have shocked it up to 32ppm FC but that did not bring it down. I've left the top open but that also did not bring it down. I've had my Ozone off since before converting to salt water.

I've found I need to run my saltron swcg at 16 hours per day and that if I start out at 4FC in the evening and 2 people use the tub for 2 hours that after 16 hours I am lucky to have 1ppm FC. I had thought the swg would emit .8ppm FC per hour according to what it states yet I end up with only 1ppm after 16 hours.

So the questions could be:
1. while the salinity is 2400 and within specs, would more salt = more chlorine per hour generated?
2. since my CC is above 1, is this presence interfering with the swg?
3. is the CYA at 40 perhaps too much buffer for the FC and not allowing the CC to drop?
4. since there is lack of off-gassing and UV help, is the CC just going to stay up, and if so
a. would turning ozone back on help
b. would MPS help here and is it really advisable to use. I was under the assumption to not if you don't have to
5. is it possible I am just anticipating the swg to do more than it should or that I have a completely illogical set of assumptions going on here?

I realize there is no "this is your number exactly" type of answer. I'm very much a detail guy and am very interested in having my water be the best quality. I'm thinking about ahh-some drain and start over but the water is stable other than the CC a little too high and FC not generating as fast as I thought it should.

Thanks for any suggestions.
 

Oly

Gold Supporter
Jun 28, 2017
1,221
Fresno, CA
Ideal CYA levels in a covered spa is a different situation than an open to the air and sun pool. The 20 to 30 ppm CYA in your spa is a good level but do check it at least once a month due to the high temps and regular top offs lowering the ppm. Most important is not allowing your FC level to drop below the minimum relative to your CYA. If your SWG cannot keep up with the demand then you should bump FC with liquid and maintain FC with your SWG.

How often do you clean or replace your filter?
How often do you drain your spa during peak season?
Do you purge your system with a surfactant prior to refill?
 

mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
@Oly
My tub is 3 weeks old. I cleaned filters once a week although there is not much to clean. I've topped off twice now but did not put my meter on it. Next time I will so I know what the dilution was. Good point on checking CYA. I have been adding bleach and did bump it up, but the swg cannot seem to keep up although the rates of output should be correct. If it has to run 24 hour then it's not the right product.

@kimkats
First thing I did was add water and dichlor, heat up to 100 and do ahh-some purge. Thanks of course to the good people here! I did the 1/2 dose 2nd treatment as well, and really hardly any color or scum was evident. The water is clear, just a little foam from kid's hair product not rinsed all the way out.

I was more concerned about the output of the swg and what I might do to optimize it, and about what I really should be expecting to maintain for CC, IF the water is in the correct state.

Thanks for taking the time to reply.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
43,412
Tallahassee, FL
You are on the right track with the great start with your pool! Well done reading and doing!

So lets what is what...............I really sounds like your SWG is not keeping up for some reason. I wonder if you are just going to have to have a habit of "helping" the SWG with a slug of liquid chlorine right after you get out of the tub just to be on the safe side. I don't have a SWG yet but I know for reading that even a proper sized SWG is not enough once a lot of people get in the pool. They have to put in liquid chlorine to "help it out". I would suggest you do the same until you get the SWG dialed in.
 

mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
@kimkats
I have been doing just that, adding bleach after I get out to make sure there is 4ppm roughly. I guess the question is whether it's something in the chemistry not optimal, the 2 person 2 hour per day bather load or the inability of this swg. From what I've read here if I start with 5ppm FC and 2 of us use it for 2 hours that's going to consume it all, but at 0.8 FC output per hour one would think the swg would output 12ppm FC (in the 16 hour run time) and that would not be consumed down to the point where only 1ppm remains.

Or maybe that is exactly how it should work. I'm wanting to keep FC at all times but thought the swg would do it.
 

mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
Yes, I opened the cover to the motherboard followed the leads and physically pulled it. I did leave the end inside the motherboard enclosure with black tape over the end so that there would be no corrosion.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,258
Tucson, AZ
You might want to purge the tub again while keeping this info in mind -


You could have residual Ahhsome in the water leading to excessive FC demand or you might have plumbing lubricant in the lines that is causing problems. After trying the above protocol, I would recommend filling the tub with fresh water, running the system and then drain it again. It’s a lot of water to send down the drain but you clearly have something in the tub that is using up your FC. If your Saltron mini is making bubbles and is not scaled up with white calcium, then it’s working. One way to test it would be to get a large water container (about a gallon or two or even a 5 gallon bucket), fill it with distilled water and salt to the correct salinity and then run the Saltron for about 15-30secs or so. With such a small volume of water, you should see a measurable FC level in no time.
 

mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
Hmm much of what you said is what I was questioning myself minus the bit about the calcium stearate. I did follow the directions on the ahh-some website and did a second dosing with 1/2 rate of first. As I mentioned, there was nothing really to notice. But I think the same, that something is consuming the FC. The saltron is definitely working. I took a 5 gallon bucket and filled it with 2ppm FC water from tub and put the swg in it. I don't know if it's output is what it should be, but it did raise it. There is no scale on the swg. Because I drop my pH probe in all the time and it's really quick to read, I was able to use MA to drive the pH/TA down in one day and it's stayed there, so I haven't noticed any calcium precipitate on the tub walls anywhere. And I've been searching with my magic eraser in hand lol. The pH is about 7.47, maybe a little above the optimum for chlorine but certainly should allow the FC to work at a decent level, and I had thought it also would allow the swg to do it's "super chlorinate" thing. I've been checking the probe (which is new) with 4&7 buffers, and it says it's correct so I am assuming that I hit the sweet spot for pH/TA as it goes up to 7.7ish after running for an hour or two, but drops right back to 7.4ish.

I have set my tub to run one jet (it's faking a circ pump) every 6 hours for 30 minutes, just so the FC the swg generates gets in the piping a bit.

I just got a bag of morton pool salt delivered as I read it would have the least impurities. I have no idea if it is better than the kosher salt I was using but regardless, I might just have to do the clean and purge again.

Short of me and my girlfriend being in the tub for 2 hours a night and consuming way more FC than the swg can put out, maybe your idea is the issue. Thanks a lot for taking the time to respond, I appreciate it.

And thanks @kimkats

EDIT: ohh, one thing. That pdf file says to have the pH around 4-5, and it looks like that is at start. That's pretty low. But then it says in the "steps" section to check the pH after it sits overnight and it should not be at 6.5 or > .. so I assume I am to use MA to drop the pH to that range? Don't want to cause any corrosion due to low pH. Any thoughts on that?
 
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JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,258
Tucson, AZ
...
EDIT: ohh, one thing. That pdf file says to have the pH around 4-5, and it looks like that is at start. That's pretty low. But then it says in the "steps" section to check the pH after it sits overnight and it should not be at 6.5 or > .. so I assume I am to use MA to drop the pH to that range? Don't want to cause any corrosion due to low pH. Any thoughts on that?
The pH that pdf is referring to is the pH you would get when adding the white vinegar they recommend to the hot tub. Do not use MA. If you don’t think it’s a calcium stearate issue, then you don’t need to add the vinegar or follow that procedure. Being at that pH for short period overnight isn’t going to harm anything.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,258
Tucson, AZ
Food based salts, like kosher salt, should not be used in a hot tub. Kosher salt doesn't contain additives like iodine BUT it can contain anti-caking agents. Sodium ferrocyanide and magnesium stearate are both common additives to salt as anti-caking agents. Neither should inhibit the SWG from producing chlorine but ferrocyanide can break down into iron oxides and cause staining. Stearates will combine with free calcium ions and cause cloudiness.

It’s best to stick to pool salt for your hot tub.
 
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mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
Interesting. I have my morton pool salt bag now I just need to know one thing before I proceed. The document says to not put the old filters back in else it introduces the stearates back into the tub. I will buy a new set but are the old ones (which are a month old) not able to be decontaminated?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,258
Tucson, AZ
Interesting. I have my morton pool salt bag now I just need to know one thing before I proceed. The document says to not put the old filters back in else it introduces the stearates back into the tub. I will buy a new set but are the old ones (which are a month old) not able to be decontaminated?
If stearates are present, they will plug up a filter and be very hard to remove just by soaking. In your case, you need to run with the filters you have until you can replace them. Also, since you’re not 100% certain stearates were an issue, then the filters should be fine until you can replace them.
 

mrwoo

Well-known member
Nov 9, 2019
54
kalispell, mt
I bought a new set of filters. When they arrive I will drain and clean with the stearate method. It sure would be nice to clean out my current filters, they are only a month old. It could be possible as well that the kosher salt introduced an issue.