High Chlorine Demand issues after refill

Mar 10, 2018
5
Petaluma, CA
Hi all,

I am having issues with my 2 month old Marquis Spirit spa. Three days ago I discovered the water was in pretty poor condition, unfortunately I had been neglecting to test it for several days. My FC was <1 at this point. I popped in a new Spa-Frog in-line bromine cartridge and shocked to 10ppm with Dichlor as I have been doing periodically. At this point I finally caught on that my frequent dichlor shocks may have led to a CYA problem, which I tested and found ~90ppm. At this point I decided to change my water, but unfortunately I didn't realize at the time I should do a flush treatment like Ahh-some. When I pulled the filter I discovered lots of leaves and plant matter covered in white bacterial grossness, so I skimmed as much of that stuff out as possible and drained the tub. I really wish I had done a flush but instead we simply drained, scrubbed and immediately refilled, followed by a 13ppm shock using dichlor.

Now that it is refilled I am having issues with crazy high chlorine demand after shocking. My initial 13ppm shock after the refill had diminished to about 1ppm in the morning (<24h). I tried again, but with bleach to avoid CYA buildup, this time shocking to 11ppm, and this morning I read 1.5. This is a almost a %90 CD in like 18 hours. After reading more about biofilms I am sufficiently paranoid and worried to go in. My tub has an ozonator but from what I am reading that can't account for this dramatic of a CD.

Is it time to accept that I may have a biofilm growing? Or is it possible I am still working through a reserve of organic material caught in the pipes that would eventually get oxidized down if I keep shocking? I have some ahh-some coming from Amazon but was hoping I wouln't have to waste all this water right after my refill, though maybe that is par for the course while learning.

The water itself seems very clear and reasonably pleasant. Very little cloudiness with perhaps a minor combined chlorine smell immediately after opening the cover.

Currently I have:
FC: 1.5ppm
CC: 2ppm
CYA: <30ppm
PH: 7.4
TA: 100ppm

Thanks so much for any help!

-Eric
 
Did you use the tub?

You should probably drain and flush. That being said I would use it until it's convenient to do so and continue to shock each day. Maybe increase the ppm amount a bit. Note that if you use the tub you want to add approximately an additional 3 ppm per person per hour of use assuming you start at 1 to 3 ppm.
 
I did use the tub once, after measuring my CD the first time. I then shocked the 2nd time after getting out and haven't been in since. Perhaps my ~30min use explains some of the the FC drop off I measured overnight? I will probably end up flushing for peace of mind, but it sounds like perhaps I shouldn't worry about using the tub for a few days first, as long as I keep shocking and testing FC?

Thanks for your advice!
- Eric
 
Welcome to TFP! :wave: While I myself am not a tub owner, there are a few principles that stand-out for all of us and some things you may wish to consider:
- Perhaps your biggest issue is what you already admitted - not doing an Ahh-some treatment at your last water exchange. There could be some issues lingering in the plumbing.
- After the last water change, you added some dichlor, but it looks like your CYA is still below 30? If the tub water is exposed to the sun, that could be part of the problem as well unless you know for sure the CYA is at least 30.
- You can try bumping the FC up for a day or so, but as you mentioned. if it doesn't work, a thorough flush may be in order.
- Have you see the TFP stickies: Spas and Hot Tubs Some good info there.

In any case, others may reply as well. If you are still having issues, reply back as much as you need. Nice to have you with us.
 
Do an ahh-some flush when it's convenient. It may take several treatments to get things cleaned out.

In the meantime I would maintain a constant chlorine level of at least 3-4 assuming your cya is 30. Then add 3 ppm per person after each soak + 12 ppm shock. It wouldn't hurt to go a few ppm higher than 12 for the shock.
 
Thanks for the advice everyone, and thank you for the warm welcome. I have no idea how people would figure all of this stuff out without communities like this!

Things seem a little better today, 10ppm shock last night (was shooting for a little higher), and added a little MPS to boost it. FC was down to 4ppm (2ppm CC) today, so still a big decrease but not quite as intense as 13->1ppm like I saw before. I am still planning on doing the purge treatment but if I can get the CD to something more reasonable I may put it off for a little while. The water is very clear, maybe still with a minor (combined) chlorine smell, if it wasn't for the CD I wouldn't have thought there was any issue...

Thanks again, will let you guys know how things progress.
 
Thanks for the advice everyone, and thank you for the warm welcome. I have no idea how people would figure all of this stuff out without communities like this!

Things seem a little better today, 10ppm shock last night (was shooting for a little higher), and added a little MPS to boost it. FC was down to 4ppm (2ppm CC) today, so still a big decrease but not quite as intense as 13->1ppm like I saw before. I am still planning on doing the purge treatment but if I can get the CD to something more reasonable I may put it off for a little while. The water is very clear, maybe still with a minor (combined) chlorine smell, if it wasn't for the CD I wouldn't have thought there was any issue...

Thanks again, will let you guys know how things progress.


It it sounds like you just don’t get it. Just do,what Texas Splash and A Robbert say about doing the plumbing purge and your problem is solved. I repeat: Every single hot tub in the world needs to have the plumbing purged at least twice a year. Why do Hot tub owners balk at doing the purge? If you want a healthy soaking environment, do the purge. If you knew how much bacteria was in your plumbing, you would purge more often. Do yourself a favor. Go to TFTestkits.net and get the purge product. End of story.
 
Hey Ahhsomeguy, don't worry we aren't 'balking' at the purge process. In fact I was planning on purchasing your product to do the purge in the next day or so, as I stated in my post. Perhaps I don't 'get it' quite yet but thanks to the help of others in this forum I am learning fast, and luckily they give it without any attitude.

Have a great day
 
Remember that MPS will show up as CC on the chlorine test. If you want to remove it's affects Taylor sells a special regent to do so, otherwise you just have to be aware of it.
 
Hi Spectral: Sorry for the way I replied to your earlier post. It was an improper way to respond based on the overall tone.
Sometimes, I get so frustrated when I see the same nagging problems over and over again where good advice is given and not acted upon. I realize you were close to the beginning of the “Purge” process and probably should have kep’t silent.
Please understand that we are not on this forum to push any specific brand of plumbing cleaner. There are many fine products on the market that will certainly help your situation. We really want all hot tub owners to fully enjoy the benefits of hot water therapy and to help eliminate maintenance issues that may give tub ownership a bad name.
 

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Thanks for the reply, no worries at all, I understand it must get repetitive answering these same questions. In fact I have probably even read 20+ similar answers from you and others about this stuff before deciding to post my own situation, so I suspected the purge would be a top recommendation, but there is definitely something reassuring about getting specific replies based on my exact circumstances and measurements. Either way rest easy, I am convinced the purge is what I need, my container of Ahh-some just arrived so I am probably going to give that a shot today!

Thanks again for all the input, here and in countless other helpful threads :)
 
Thanks for the reply, no worries at all, I understand it must get repetitive answering these same questions. In fact I have probably even read 20+ similar answers from you and others about this stuff before deciding to post my own situation, so I suspected the purge would be a top recommendation, but there is definitely something reassuring about getting specific replies based on my exact circumstances and measurements. Either way rest easy, I am convinced the purge is what I need, my container of Ahh-some just arrived so I am probably going to give that a shot today!

Thanks again for all the input, here and in countless other helpful threads :)

Very Important: Do not overdose with the gel. You only need 3/4 teaspoon for every 100 gallons.
For spas up to 450 gallons you would use no more than 3 level Teaspoons. Most people use too much.
More is Not better. Be sure to not let the product stay in the tub overnight. 30 minutes is all you need.
Also, be sure to remove any pillows or headrests if possible. Biofilm is very sticky and can stick to the shell or pillows with a vengeance. Use a micro fiber cloth or a old towel to wipe away the released gunk. Lastly, remove the filter(s), hose them off and place them INSIDE the hot tub while purging. That’s It.
 
Hi Osonurse: So glad that you did the Purge and that your water is now easier to balance. Going forward, you should notice a clarity that is stunningly clear. Most importantly, the ability to contract the hot tub rash should be zero providing you maintain proper balance and always have sufficient sanitizer present while soaking. Lastly, your question on cleaning the filter(s) is a good one. We highly recommend that you hose the filter(s) off to get the major trappings removed. Then, we recommend placing the filter(s) into the hot tub proper while purging. This will allow for a very thorough cleaning and removal of whatever may be growing deep within the pleats. This is recommend for all pleated fabric or Reemay material filters. We do NOT recommend doing this for the non fabric pleated filters that you see on many of the newer hot tubs. We have noticed that some of the gunk that is being removed will stain the material. Lastly, if you want to whiten the filter(s)after purging just spray some “chlorine bleach” on them. They will look like new. You would be fascinated to learn about the amount of bacterial gunk that can be dislodged when you clean the filter(s) this way. Some very nasty contaminants can be found in most filters no matter how well the hot tub water is maintained.
 
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