New Spa owner - Questions regarding water changes, biofilm, and @ease

Certified106

Well-known member
Sep 10, 2018
101
Athens, Ohio
So I originally added my chlorine and had a reading of FC being 12.5 at around 6PM

At 9PM my Reading was

FC: 10
CC: 0.5

at 5:30AM

FC: 7.5
CC: 1.0
TA:60
PH:7.8

Is that kind of drift typical?
Also I'm not sure what to think of my CC reading being a 1 already and is the FC loss to high? Is it possible that the CC came up due to neutralizing nasties from the Ahhsome purge?
 

jza1736

Silver Supporter
Apr 21, 2017
536
Greenlawn, NY
Your cc at 1 or less is fine. The fc loss is probably from the leftover Ahh some or biofilm. I would keep a close eye on it for a few days. Make sure your fc doesn't drop under 2
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,284
Tucson, AZ
Residual ahh-some in the lines and water will show up as both a slight FC demand and create CCs upon chlorine oxidation. Continue to elevate the chlorine up to 10ppm and keep the cover off the tub for a few an hour or so each day. That will help to oxidize any further organics and offgas the CCs.
 

Certified106

Well-known member
Sep 10, 2018
101
Athens, Ohio
Residual ahh-some in the lines and water will show up as both a slight FC demand and create CCs upon chlorine oxidation. Continue to elevate the chlorine up to 10ppm and keep the cover off the tub for a few an hour or so each day. That will help to oxidize any further organics and offgas the CCs.
Well I made a judgement call before leaving for work and gave the tub a very minor does of Acid .2oz and another 1.5ozs of bleach for the exact reasoning you stated...….Yay I did something right. It is Supposed to rain pretty good for the next few days but I will get it opened up tonight for an hour or so. I was hoping it would be sunny today and help me get rid of some of the CC.
 

Aqua Lab Rat

In The Industry
May 1, 2015
120
Anoka, MN
Just wanted to throw in a couple cents here.

When using a spa flush product, I always do a couple of things: I have a shop vac handy and occasionally suck the gunky green and yellow stuff off of the foam. That way it doesn't stick to the side when you drain. Second, I always shock the spa before shutting the jets off and draining to kill things off while it is vulnerable.

I didn't see any discussion of calcium hardness in the early part of the thread where foaming was being discussed. Even though the hydantoin in some spa sanitizers may increase potential for foaming, having low hardness (regardless of sanitizer) can also contribute to foaming.
 

Certified106

Well-known member
Sep 10, 2018
101
Athens, Ohio
Just wanted to throw in a couple cents here.

When using a spa flush product, I always do a couple of things: I have a shop vac handy and occasionally suck the gunky green and yellow stuff off of the foam. That way it doesn't stick to the side when you drain. Second, I always shock the spa before shutting the jets off and draining to kill things off while it is vulnerable.

I didn't see any discussion of calcium hardness in the early part of the thread where foaming was being discussed. Even though the hydantoin in some spa sanitizers may increase potential for foaming, having low hardness (regardless of sanitizer) can also contribute to foaming.
Thanks so much for the input! Wish I would have thought of the shop vac thing but honestly there wasn't much sticking to my tub. I did have my free chlorine raised to about 8 before starting the flush so hopefully that helped but next time I will definitely shock it really good and then circulate the water even more. When I was having the earlier foaming issues the CH was reading 150ish on a test strip so who knows if that was an actual number.

Let me ask you or other this though, We used it for the first time last night (about 30 minutes) and when we got done there was a little bit of a scum ring around the edge of the tub in certain places. Do you all think that is still some residual of the Ahh-Some even after I filled it and then drained it following the flush? It felt fairly slimy and sticky. What really puzzles me is that I ran the blowers for two hours while knocking the TA down and didn't notice any scum line nor have I ever had an issue with one other than when we went on vacation.


Also for those of you who have been helping me out or following this thread I really want to thank you for all the help. my TA has been hanging steady and even after using the tub last night when I checked PH this evening it was sitting steady at 7.4! This is the first time ever that I have had control of PH and TA in this tub and it's all thanks to you. the Chlorine was about 8 when we got in last night and I added 3 ozs of bleach when we got out which way over shot the chlorine levels and when I checked it this evening they were still at a ten. It will take me a bit to get the hang of how much chlorine it needs but I will get the hang of it soon. Oh by the way the CC has been hanging out at about .5. The only thing I'm not happy about was the scum ring last night I just wish I knew what it was.
 

jza1736

Silver Supporter
Apr 21, 2017
536
Greenlawn, NY
Might just be some leftover from the Ahh some. Do your have a scum sucker? They come in all different sizes/shapes?

They soak up oils, sunblock, scum

I have a 600 gallon spa. When it's just me and my wife for an hour or so, I'll use 2 oz of chlorine. If it's open all day and more people, the most I'll need is 4oz.
 

Aqua Lab Rat

In The Industry
May 1, 2015
120
Anoka, MN
Yeah, probably just some remnants of the flush coming out of the lines. I don't have experience with Ahhhsome, I use SeaKlear Spa System Flush. Just wipe it up and you should be good to go. Maybe it was kept suspended when the blowers were running and then settled out along the waterline when the water got calm.
 

Ahhsomeguy

Gold Supporter
Silver Supporter
In The Industry
Jul 26, 2016
136
Vero Beach, Florida
Aqua Lab Rat is correct. Just wipe the small amount of brownish residue with a cloth. This can occur after a complete hot tub purge. A good flush product has to penetrate the biofilm outer layer to gain entry so it can begin dispersing and lifting the gunk from the colony. This is why all flush products want the user to run the pumps as the flow of water helps to carry this detritus material into the hot tub proper. Sometimes, small amounts of the sticky gooey stuff is almost broken free but is still hanging on. A few days after running the hot tub it breaks loose and this is what you are noticing. No big deal. Just wipe it up. Now, for Certified 106. You did good. Start enjoying your hot tub. The water chemistry testing you are doing is great to learn for new owners. However, now is the time to back off a little and Follow the basics. Once you removed most of the biofilm, as you did, your water maintenance will be very easy. Do check pH, alkalinity and cyanuric acid periodically, but don’t be paranoid about it. The important thing to check on a regular basis is the amount of available sanitizer you have. One of the best investments you made was getting the TF test kit. After a few weeks you’ll get to know your tub’s requirements. It will become second nature for you. Just purge and drain the hot tub at least twice a year, adjust water to accepted chemical parameters, maintain adequate sanitizer at all times and you will be enjoying crystal clear healthy water. Enjoy!
 

Oly

Gold Supporter
Jun 28, 2017
1,657
Fresno, CA
I'll bet many folks who enter a hot tub have lotion or creams somewhere on their body and this gets washed off, suspended in the hot water and deposits on the sides of the tub.
 

Certified106

Well-known member
Sep 10, 2018
101
Athens, Ohio
Well aftter almost a week of using the tub I have not had to make one single addition to the hot tub for PH. We used it last night for and hour and then again this mornign for an hour as well as multiple times this week and this is what my PH looked like afterwards!

Still after being in it for 20 minutes or so I start to see a little bit of whitish/tanish scum on the side of the tub that I have to wipe off. At this point I'm wondering if it's just body oils from sweat or lotions that weren't completely rinsed off that are just floating on the surface. No yellowish residue like right after we purged the tub. I'm still not used to seeing any scum line at all but part of me wonders if it could be due to switching to the bleach method and having more chlorine in the water than before which is neutralizing things faster?


This kind of blows me away...…. I measured the FC at 5 before getting in this morning and two of us spending an hour in the Hot tub. An hour after getting out the FC was 3. does it really take that much FC to neutralize 2 people in there for an hour?




 

Certified106

Well-known member
Sep 10, 2018
101
Athens, Ohio
Wanted to provide a quick update...... Figured out why I was having some scum on the edge of the tub yesterday. I was thinking about it and realized right after I refilled there was still some junk being broke loose and maybe the filter was dirty even thought it has only been a week. Pulled the filter yesterday and it definitely had junk that it had filtered out all over it. I bought a new filter and installed it and after using it for an hour this morning there wasn't one single drop of scum anywhere on the edge of the tub and it was crystal clear. From now on when I do a fresh refill I am going to pull and clean the filter a few days after the refill.

I washed out the other filter with the hose last night and it bubbled like crazy but looks a lot cleaner. I will get it soaking in bleach today and have it ready to go back in shortly.
 

Ahhsomeguy

Gold Supporter
Silver Supporter
In The Industry
Jul 26, 2016
136
Vero Beach, Florida
Hello Certified106: So glad to hear that your high sanitizer demand has moderated. You should now a believer about the benefits of doing an effective plumbing/jet purge at regular intervals. Keep up the good work.