chlorine level and SWG

[Pklambooy]

27000 gallon, in-ground, vinyl liner
water is clear
pH 7.2
TA 200
salt using TFTestkit is 3800, by paper strip is closer to 3000
CYA 80
Cl 1 by Taylor R-0600
RC-52 SWG putting out 20 volts, 5.1 amps

i have been wanting to keep my Cl closer to 3 to minimize risk of generating cloudy water. I’m running SWG at 80%, and even had a couple days at 100%.....Other than the high TA all the info suggests everything is ok, but I’m surprised I can’t bump the Cl quite a bit higher...am I over-reacting to the “low” Cl even though I know one advantage of a SWG is lower Cl levels? Though new it’s also possible Cl reagent not good (don’t have strips currently).

 

[duraleigh]

You should be using the FAS/DPD chlorine test. It is powder and liquid both and is in the TF-100.

It looks like you are only using the OTO chlorine test (reagent R-0600) which is not accurate enough for what you are trying to do.

 

[mknauss]

[FC/CYA][/FC/CYA]

At a CYA of 80 your Target FC is 6 ppm. Use liquid chlorine to get to 6 ppm then use your SWCG to maintain it.

Your SWCG can create 2 lbs of chlorine per day at 100%. So it is plenty large enough for your pool. If you cannot get it to hold your 6ppm FC then you should do a Overnight Chlorine Loss Test to see if you have something growing in your pool water.

 

[Pklambooy]

I did toss in a couple of 1lb bags of calcium hypochlorite the other day to give it a little shock to see if that would help raise level.

 

[Pklambooy]

Will also carry out DPD-FAS test

 

[Pklambooy]

Update. I opened pool and got in. I must have some organic growth since the vinyl floor was a little slippery and water not crystal clear. I added chlorox to kill.

 

[mknauss]

SLAM Process. It is not a one time addition of chlorine. Use [FC/CYA][/FC/CYA] for your shock level.

 

[Pklambooy]

Adding more chlorine...did I initially “hurt” myself by being near the edge of a good chlorine level by having a pretty high level of CYA....?

 

[mknauss]

Not sure what you mean by 'hurt' yourself. Chlorine always is good. Just sometimes you need a lot more than other times.

 

[Pklambooy]

12 gallons of 6% so far....

- - - Updated - - -

By “hurt” I meant since my CYA was higher than normal I assumed my FC level was still okay not knowing it needed to be higher to prevent growth at higher CYA.

 

[Pklambooy]

I added a total of about 16 gallons of bleach, FC was now at 5.5, CC at 1.0 using DPD-FAS. I tossed 4 more gallons in, water much clearer....will check later.

 

[domct203]

I added a total of about 16 gallons of bleach, FC was now at 5.5, CC at 1.0 using DPD-FAS. I tossed 4 more gallons in, water much clearer....will check later.

Are you attempting to SLAM?

With a CYA of 80ppm, your FC should be maintained at 32ppm.

 

[Pklambooy]

I think the contamination I had was pretty mild. I have kids coming in a couple days so want to be a little careful so as not to have too high of chlorine. I tossed in more chlorine this morning. FC is now 11 and cc 1-1.5. Pool water quite clear. I'll do another test tonight and maybe add more chlorine or not. Running my SWG at 100 % I'm hoping by Saturday FC might come down a little and with a clear pool ought to be satisfactory?

 

[mknauss]

You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.

You would be better off getting the FC to SLAM level and eliminate the CC. The CC will cause irritated eyes and chlorine smell.

 

[Pklambooy]

Thanks! Yes, bottom of pool easily seen. I will add more chlorine, thanks again! This CYA level really through me for a loop. I knew a hefty level was good but didn't realize the unintended consequence of needing more FC.......

 

[Jwmote]

12 gallons of 6% so far....

- - - Updated - - -

By “hurt” I meant since my CYA was higher than normal I assumed my FC level was still okay not knowing it needed to be higher to prevent growth at higher CYA.

If you are using a SWG it actually likes a higher CYA.

With a CYA of 80 you want 4 Minimum FC, Target FC of 6, and shock of 31. The nice thing about salt is once you get it running and use bleach to get it at target level it is very easy to maintain.

you can use SWG Run Time Calculator

to see how long to actually run your generator and what percentage to run it at to maintain your target level. You will want to do a 24 hour chlorine demand first though. Basically you get your chlorine to your target level and test. then the next day at the exact same time test again and compare the difference. that tells you what your daily loss is and you can plug that into the calculator above.

In addition you will need to know the 24 production of your generator which is usually in the manual. I believe someone earlier said it was 2 lbs but not sure.

​

 

[Pklambooy]

Thoughts on using the bags of calcium hypochlorite to assist in shock? Pool now at FC of 8, CC down a bit to 1.

 

[Pklambooy]

And running SWG at 100 %.

 

[mknauss]

What are you trying to achieve? I thought you needed to SLAM? A bit of cal hypo and your SWCG will not achieve that.

 

[jimmythegreek]

You have to follow a serious slam routine. That cc of 1 or more is bad stuff still in water. Bump it up to 30 fc and hold it as long as u can u may only need 2 to 3 days to clear the #s if ur water is clear