Struggling with cyanic acid and water balance

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Matilda

Matilda

Active member
Dec 3, 2017
37
West Yorks/UK
Hello,
Hoping someone can offer some clarity for me ! I've been running my hot tub for a several months and seem to be in a constant battle with chemicals and balancing the water. The main problem is slightly cloudy water and ever increasing cyanuric acid levels:(
My dealer told me nothing about this and encouraged us to buy these 'best test strips'. When I asked about the CYA levels and having to drain the pool down around every 4-6 weeks they told me not to worry 'we don't really test for that or know anything about it ! This seems to be a common perception of it where I am in the UK. I wasn't really satisfied so I did some digging around and came across this site.

It's been a real eye opener !

I refilled the pool 2 weeks ago and CYA is already up at 100 :mad: I've read through the forums and looked at the the dichlor then bleach method but I can only seem to find sodium hypochlorite at 14-15% which says it's for pools.

Does the bleach method damage the internals at all ? Also I've always used bleach in the house in cold water as always though that heat made it less effective ?
[h=3][/h]I'm searching for a more comprehensive test kit and I can see the Taylor one recommended isn't available over here.

I'm looking to buy the Lamotte one but I'm wondering whether to switch to bromine - I don't know anything about this method and wonder if it's as effective as chlorine ? Does it have any particular issues ( similar to the whole CYA/chlorine dilemma).


I'm so fed up with constantly draining and the advice I've had so far is to add oxidiser/shock weekly/use spa clarifier/foam away - generally just buy more stuff !

It's really getting me down and instead of being fun and relaxing it's turning out to be almost a full time job !

Apologies for all the questions and any help much appreciated, I've been reading so much I'm getting myself confused :confused:
 
Welcome to TFP!

Not sure if you saw the spa section of the forum or not but there are two startup methods listed in there, one for chlorine and one for bromine.

The % of sodium hypochlorite will only change the amount you need to dose the water with to maintain the proper FC level. You can use 6% household bleach or the higher concentrated "pool" bleach just make sure you adjust the percentage in pool math to determine the amount needed.

A quality test kit makes caring for you spa easier, what ever kit you purchase make sure it has a FAS-DPD chlorine test.
 
Many thanks for replying AftonJeeper, yes I've had a browse. I'm just wondering whether switching to bromine will be as effective and easier to manage. I'm a bit worried about adding incorrect dosage with bleach with the higher concentration and I can't seem to find any 6% most of what I've seen readily available is less than 5%. I've contacted Sword shield today about the lamotte 7022 kit and they've said they no longer supply it as it doesn't comply with standards ? They also said they don't supply any FAS- DPD kits so I'm stumped as to where to find one in the uK as it seems we have limited choice here !
 
Bromine will not work any better than chlorine and bromine can have it's own problems as many bromine tablets are composed of BCDMH where they add dimethyl hydantoin (DMH) continuously to the tub. DMH causes similar problems to using too much CYA but there is no test for DMH so you only know how much you have based on keeping historical records of tablet use. So bromine is not a better solution...also, many people are more sensitive to the smell of brominated waters and some report greater skin sensitivity to it (although that is mostly anecdotal evidence). So if you don't have any problems with chlorine, stick with a chlorine tub.

I'm not surprised that shops in the UK have no idea how to deal with CYA because it's not used much in the EU and UK pool regulations. Also, test kits can be very expensive mostly because they have to be shipped in from the US. LaMotte is your best bet for getting a usable test kit as they are a European manufacturer. In the US we use Taylor Technologies but their stuff is limited in Europe and the UK because they have to rely on distributors there....so a lot more middle-men taking their cut.

Using bleach in your tub should be fine. As far as chemistry is concerned, bleach causes on a small net increase in pH over time while dichlor is acidic and will cause a net decrease in pH. Using bleach is safer than dichlor as it adds no stabilizer (CYA) to the water and will not cause the pH to crash. Low pH is going to be the biggest driver of damage to internal equipment in a hot tub.

If you stick with the dichlor/bleach method in the sticky and follow the instructions there carefully, you should have no problems keeping the tub balanced. You might need to simply drain the tub now to get rid of the excess CYA and start with a fresh fill. I also suggest you look into to doing a plumbing purge to get rid of biofilm accumulation using a product called Ahh-some. If you can get Ahh-some in the UK through a distributor, it is well worth it. You can look up Ahh-some on the internet and contact them directly, they can help you find a distributor. The company owner is a TFP user (ahhsomeguy) and he will happily help out with product advice.
 
Thanks JoyfulNoise for taken the time to answer. Very helpful ! I'll stick with the chlorine and I've just cleaned out the pipework and in the process of refilling - not much fun on an icy December morning ha ha

I've been reading through a number of threads but getting confused over the all the ratios but I'll keep reading until it finally goes in !

It doesn't seem we can get the lamotte test kit anymore over here - I have found the Taylor Icare one though ? Is this any good for accurate testing. I don't really understand the difference between the FAS- DPD and just DPD ? The Icare says it tests for TC FC and CC - is this what is needed ?
This is the kit I've found Taylor Test Kit - The Swim Store


Edit * I've managed to find this one: Taylor K- 2006 FAS- DPD kit Chlorine swimming pool kit


I don't think it comes with as much stuff as the 2006C kit, could anyone kindly advise me what reagents I'll need most of so I can order them with it - I don't fancy paying £60 postage each time for refills ! :pth:

Again Many thanks and much appreciated everyone
 

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The difference between the FAS- DPD and just DPD-

FAS-DPD is a powder based test. It is great as you can test your FC as high as you might need to. It is more accurate that the DPD test. If I use the DPD (a drop based test) at all it is just to tell me there is some FC in the pool.

I would say you need more of these test as they are the ones we use daily:
-FAS-DPD
-PH

I would also get more of the CYA test regent as the 2006 only gives you a couple of test worth of regent.

I would also like you to look into this test kit:

Total Pool Water Testing Kit, Fresh Water Clear Choice Labs

I don't know how the shipping will be for you from them. It is worth checking into. They have proven themselves to our friends in Australia.

Let me know if I missed a question or concern. :hug: we want you to enjoy your pool!

Kim:kim:
 
Thank you so much Kim !
Everyone's help so much appreciated :D

Sorry for delay in replying, crazy rush up to Christmas with business !

I've now got my Taylor kit - shipped from USA :kim:

Managed a quick test yesterday and my goodness - how right you are about inaccuracy of those test strips !! :bowdown:
 
I was so excited when it came, it was like my favourite Christmas present !:whoot:
The test showed up some interesting results ( I had an idea they'd be way out from the strips) so just trying to get my head around what I actually need to do now !

These were my results
PH -8ppm
CYA - 80ppm :rolleyes:
Chlorine - 5ppm
CC's - 1.5 ppm
TA - 110ppm

Didn't do the calcium one as it got real dark quickly !
Looking like I'm draining down once again :brickwall:

I've already ordered refills for some of the test ( as you suggested) so I don't run out and I'm just about to get sodium hypochlorite - looking like I'll have to get the 14/15% strength as I can't seem to find regular household above 5% over here. I must admit I do feel somewhat nervous about using it but I've had enough of the ever rising CYA !
 
I've just re-tested the spa and these are the readings:

PH - 7.8 ppm
TA - 110 ppm
CYA - 80ppm
FC - 1ppm
CC - 1.5 ppm
CH - 90ppm

The Saturation index on the Taylor water gram is 0.1
The CSI on the pool math calculator is 0.3
Are these the same thing ?

So I'm thinking the water is fairly balanced ?
But I need to shock it ( due to CC levels ) and part drain it ( due to CYA levels)
Also add chlorine to raise levels 6 ppm ( as suggested in PM calc) - I raised it to 5ppm 24 hours ago and it's lost 4ppm since then - CC's have remained the same.
Does everything else seem okay ?
Sorry, I'm getting a bit confused on the pool math calculator and think I'm getting a bit mind boggled with it all :confused:

Also my hubby has been mentioned getting a salt chlorinator ? Just to give me a bit more to think about :drown:
 
I am going to back us up a step or two first..........

Did you do a "cleaning" when you first brought the spa home? I have heard from any that own and care for spas that the pipes are a mess in the beginning. We have found this product really works for cleaning the pipes and such:

https://www.amazon.com/dp/B0030MYGXW/ref=asc_df_B0030MYGXW5317499/?tag=hyprod-20&creative=395033&creativeASIN=B0030MYGXW&linkCode=df0&hvadid=198056903981&hvpos=1o3&hvnetw=g&hvrand=4843821600891639448&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9011580&hvtargid=pla-319504353029

With your CC at 1.5 is what makes me wonder if you need to do a gut cleaning when you are able.....I am going to share a link you might have already seen but want to give it to you just in case you have not:

How do I use Chlorine in my Spa (or pool)?)

Let me know if this is helpful and makes sense to you.

Kim:kim:
 
Just an FYI, pH is not measured in “parts per million” (ppm). It’s just a number and it ranges from 1.0 (acidic) to 14.0 (basic) with 7.0 being neutral pH.
 
We only drained the tub on the 9th December and cleaned the pipes then with jacuzzi pipe cleaner - which we left in overnight too.
It's had a Deep clean another two times before this - once again with the jacuzzi stuff and once with Aquafinesse spa clean. So 3 times in total !

We've also deep cleaned the filters regularly too ( which is a right royal PITA with 5 of them !)
[h=1][/h]Yes I've read the chlorine in my spa thread, I'm finding the variables for the different chemicals confusing but I think I may get a better hang of it now I've got a better test kit so I can actually see what's going on :D

I can't understand why the CC's are so high, I've shocked this eve and added the amount of dichlor as suggested in PM calculator with my readings - it gave recommendation for 6 ppm (14g dichlor) but now FC is reading at 9 ppm ! CC is the same.

Thanks for responding Kim, I really appreciate it.

Joyful Noise, thanks for the correction - habit ! ha ha
 
Okay, so I did a FC overnight test and went through Nitros post again :)
Readings this morning are
PH 7.8
TA 100
CH 80
FC 4
CC's 0.5

So cc's have come down and saturation index on water gram is showing 0
It's used 5 ppm of chlorine overnight - is this bad ?

I also tested my CH on the outdoor tap where I fill from and that was 180.

So there's a difference to what it is in the tub now and fill from tap, does anyone know what's caused this and do I now need to add calcium hardener to bring it up over 100 ? or is it ok because it's balanced ?

Am I right in thinking the water is balanced because I have higher TA and PH readings and low CH ?

The only issues I've felt I've had with the tub is the high CYA levels and cloudy water occasionally ( but then I usually drain down - which I want to avoid doing every 6 weeks or so )

We've never had itchy skin, burning eyes or anything like whenever we've used it or any other obvious ill health.

There have been times when I've cleared biofilm with clear spa (sludgy green or purple coloured on the sides) after very heaving use and I suspect people have had moisturiser on and a couple of times when my daughter's decided to jump in with self tan or make up on ( which she's now stopped after a few ear bends ! )

Tub has been deep cleaned since these episodes.

Again any help much appreciated, I really want to get this right ;-)

Oh and I've ordered some ahh some - looks great, thanks for that !
 

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