Suspected problem in hot tub...chlorine demand

Mar 30, 2015
133
Dallas, Texas
So last night there was a weird thick white foam when my wife and I were in the tub. Thought nothing too much of it until this morning when I went out to test and the water was cloudy / and had zero FC.

So do I dump the water and start over or simply super shock to kill all the bugs?

Sent from my SAMSUNG-SM-N910A using Tapatalk
 
How old is the water? What size is the tub? I think either way you're still going to have to shock the water.

If you do dump it, I would suggest the use of some Ahhh-Some to clean out the pipes.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
 
Tub is only about 2 1/2 months old. 350 gallons. First filled mid-September when I got it. I added bleach and got the FC to 10 last night and it was back at zero this morning.

Started reading more this morning....is this a bio film issue?

Sent from my SAMSUNG-SM-N910A using Tapatalk
 
How often have you been using it since installation? How have you been chlorinating? If it's with bleach, are you sure it wasn't an outdoor, scented or splash-less bleach you may have used?

Even new tubs can benefit from an Ahh-some treatment. After being pressure tested at the factory, water remains stagnant in the lines in the nooks and crannies until the tub is installed. There may have been biofilms even in a new tub. I'd drain and do the treatment.
 
How often have you been using it since installation? How have you been chlorinating? If it's with bleach, are you sure it wasn't an outdoor, scented or splash-less bleach you may have used?

Even new tubs can benefit from an Ahh-some treatment. After being pressure tested at the factory, water remains stagnant in the lines in the nooks and crannies until the tub is installed. There may have been biofilms even in a new tub. I'd drain and do the treatment.
Been using probably 2 or 3 times a week. And I've been adding bleach everyday. It was weird because the water was clear the last night my wife and I tubbed however there was thick white foam when we had the Jets going....no foam when they were off. We dosed with 4 oz of 8.25% bleach when we were done. Next day (yesterday) I came home to cloudy water and no FC. I dosed again with 10 oz then came back an hour later and had only 2FC. Added another 10 oz and it raised the FC to 10 after an hour. Let it sit and this morning it was at zero again. I just want to make sure I don't get bio film. From reading it seems like a mess to get rid of. I also might switch to bromine if I dump and refill. I hate adding bleach everyday.



Sent from my SAMSUNG-SM-N910A using Tapatalk
 
Use your current water to do the Ahhh-Some treatment with, that way you don't have to dump and fill twice.

As for bromine, you still need to add an oxidizer (bleach or MPS) to oxidize organics and convert bromide back to bromine (sanitizer). So I'm not sure you'll save yourself any effort by switching to bromine but perhaps there's a bromine hot tub user that can chime in.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
 
Very low CH can cause foaming as well, but not likely to happen suddenly like that. It's not that hard to remove films that may have built up in the plumbing, just an ahh-some treatment will do it. Maybe 2 treatments if you want to get a real deep clean.

You can certainly switch to bromine as it is a little less hassle to dose if you use the bromine tablet feeder method. My spa was bromine for a while but I just don't like the odor of bromine. You may also have to change the water more frequently if you sanitize exclusively with bromine tablets and not the method of oxidizing bromide with bleach.
 
Ok Thanks for the reply. I'll just do the ahhsome treatment and start over. Should I raise the FC high prior to dumping to try and further kill off any organics in the water at the same time I add the ahhsome?

I'll just stick with bleach since I use it for my pool. How often should I dose though? If I don't go in is it normal to have to add bleach daily?

Sent from my SAMSUNG-SM-N910A using Tapatalk
 
Ok Thanks for the reply. I'll just do the ahhsome treatment and start over. Should I raise the FC high prior to dumping to try and further kill off any organics in the water at the same time I add the ahhsome?

I'll just stick with bleach since I use it for my pool. How often should I dose though? If I don't go in is it normal to have to add bleach daily?

Sent from my SAMSUNG-SM-N910A using Tapatalk

See HERE for more information on Ahh-Some. I wouldn't waste too much bleach if you intend to dump it. Just keep adding FC until you're ready to dump.

As for the frequency of chlorine additions, it's something you're going to have to dial in as there's no pre-determined schedule that generally applies to all tubs. It is not uncommon for a unused hot tub to lose a few ppm per day but only you can determine the FC demand. Most hot tubs, I believe, are set to circulate regularly to keep the water moving, so based on that schedule and how often you use it, you could need to add bleach daily. Just like your pool, you're going to have spend some time testing daily or more frequently to figure out what the chlorine demand is.

If you search on TFP with terms like "dichlor then bleach method" and "chem geek" (he's written extensively about hot tub chemistry as well!!), you should find a lot of posts with lots of helpful information including what the FC demand is for a given number of person-hours (bather waste) in a tub.
 
After your fresh refill you need to start off using Dichlor, not bleach, so that you build up some CYA. You cumulatively add around 33-44 ppm FC using Dichlor (usually takes about a week, depending on bather load) and then you switch to using bleach. About once a month, you use Dichlor for a day to make up for CYA loss.

You add an amount of chlorine proportional to your bather load. You add whatever it takes so that you still have a chlorine residual 24 hours later. You need to add chlorine in between soaks unless you add enough after a soak to last until the next soak. The rough rule-of-thumb with no ozonator and soaking in a hot (104ºF) spa is that every person-hour takes 3-1/2 teaspoons of Dichlor or 3-1/2 fluid ounces of 8.25% bleach or 7 teaspoons of non-chlorine shock (43% MPS) to oxidize the bather waste. With an ozonator, the needed amounts may be half or less.

See the sticky Using Chlorine in a Spa.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thanks for this info.

I've owned this hot tub since we bought the house three years ago, and have never done any treatment like this, so I'm afraid to see what is going to come out of my tub.

Well, I would say be more afraid of leaving it in there. Hot tub rash (Pseudomonas aeruginosa) is a nuisance, legionella (Legionella pneumophila) is potentially life threatening.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
 
Well, I would say be more afraid of leaving it in there. Hot tub rash (Pseudomonas aeruginosa) is a nuisance, legionella (Legionella pneumophila) is potentially life threatening.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

Right...


I just did the ahhsome treatment, and it did produce some gunk, but nowhere near as much as I was afraid might be there.....certainly nowhere near the amount present in the video on the ahhsome website.
 
Right...


I just did the ahhsome treatment, and it did produce some gunk, but nowhere near as much as I was afraid might be there.....certainly nowhere near the amount present in the video on the ahhsome website.

Did you throw the filter in the water while it was circulating to clean it or was it a new filter?

I think the peace of mind knowing that the pipes are clean is well worth it.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
 
I did take the filter out of the housing and put in the hot tub while the treatment was going on.

After the treatment, I drained the hot tub, scrubbed the gunk off the sides, and am now refilling it. It's almost full, so I turned on the circulation and added a tablespoon of dichlor.

I'm going to turn the jets on for 30 minutes once it's totally full.

After that, I'm supposed to drain again?
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.