Ph Good, ORP Good, FCL low to zero (intellichlor/intellichem)

[mrsol]

Hello. First time poster/user. New gunite pool/spa owner. I have heard such good things about this community, looking forward to learning from each of you

So i tested my water manually this week, and last week, and I am showing good ph, good orp, but fcl is low to zero. Alk is good too, salt is 4000ppm. Our water here is incredible hard, so our "hardness" is off the charts.

I've cleaned the intellichlor, the lights all show green, and I see the lights that indicate how much CL is being generated, and all those lights are green. But my fCl is low. So I've been putting in liquid chlorine last few weeks.

When I look at intellicenter, the intelichlor section says "managed by intellichem", but also says for the spa, output is 5%. The pool is currently winterized and not part of the circulation. They use the same system.

Should output be 5%? I asked a friend who has a similar setup and his is set to 100%. Is there a part of the system I am missing that should be helping keep chlorine levels appropriate?

Thank you.

 

[Lake Placid]

ORP is not a replacement for reliable testing. It’s a measurement of conductivity of the water which can be correlated to a theoretical amount of HOCL in the water relative to Temp and PH. What test kit are you using? What is your CYA level? CYA can interfere with ORP probe readings. When was the last time you cleaned the probe? What’s it age? How is it stored over winter if you remove it?

It’s not atypical to have a lower output percentage for your SWG in spa mode vs pool mode. What model SWG do you have?

 

[Brushman]

Hey MrSol! You're doing great and will be an expert before you know it. Every pool and spa is a little bit different and you may be a bit low at 5%. Your friend is incredibly high at 100%. I would bump your spa cell output to 20% for a couple of days and retest your FCL. As you know, with a properly functioning cell you should not have to add chlorine manually. The other thing you might think about is testing to see if you have a spread between total chlorine and free chlorine. If you do find a spread there, you should shock to get TC and FC back together again. High fives to SLC!

 

[proavia]

Welcome to TFP!

Post a full set of test results from one of the recommended test kits.
Test Kits Compared

FC
CC
pH
TA
CH
CYA
Salt
Water temperature

Is your pool an indoor or outdoor pool?

What model SWG?

Pool Care Basics
FC/CYA Levels
PoolMath

 

[mrsol]

Thank you all for the prompt replies. All the rumors are true about this group!

I'll update my profile with equipment info, but to reply here, we have the SWG model IC-40. It was installed in October, and I have not cleaned the probe yet (wasn't aware I needed to, guess I'll be doing some youtube searching later today). CYA level is 5 (very low), but the employee at our local Leslie's pool supply said because our pool is winterized and not part of the equation, we didnt need to worry about CYA until we opened the pool -- like I said, I'm new to all of this so I assumed she was accurate.

The test where I discovered everything was off was done at Leslie's pool supply. Since then, I've used what the pool contractor left us which was a little red bottle of strips called instaTest. I'll checkout the recommendations on @proavia 's post and order one of those kits.

The SWG is used all winter for the spa, so it is never stored.

From Leslies (and a recent instatest)
FC = 0
Total CL = 0
pH = 7.3 (recommended for our hardness to keep calcium flakes in the water)
TA = 90ppm
CH = 814 (like a I said, off the charts)
CYA = 5
Salt = 4000
Water Temp = 104 (once a day for 5 hrs in the evening, then normally set to 60, so temp usually gets down to 70-80 before it starts heating again)

Both bodies of water are outside but covered with automatic covers.

Thank you!

 

[proavia]

You have a combine volume of around 40,000 gallons. If both the pool and spa are controled by the Intellicenter, use 40,000 gallons for determining your dosing requirements.

We recommend a CYA level around 70 in summer. Maybe CYA 60 will work in SLC area. Your ORP won't be very accurate with CYA in the water. And you need CYA to help keep FC in the water and not over work your SWG.

We recommend a SWG at least 2x the pool volume. In your region, you can probably get by with a SWG 1.5x your pool volume. Once your IC40 is expended, consider replacing it with an IC 60.

Suggest getting one of the recommended test kits ASAP and taking control of your pool.
No one will take better care of your pool than you.
The TF-Pro Salt test kit would suit you well.

 

[ajw22]

Your IntelliChem will not work well with TFP Methods. You need to decide which direction you want to go.

Trying to mix methods will become confusing unless you do a bunch of studying on the limitations of the IntelliChem and why TFP Methods are the way they are. Or you can just follow TFP Methods learning the how and not need to be concerned so much with the why they work.

Pentair IntelliChem - Further Reading

www.troublefreepool.com

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[mrsol]

So TFP methods are all manual? Rendering the intellichem useless?

I don’t understand, do you mind elaborating?

Thank you!

 

[mrsol]

Nevermind, I read the article you linked to.

Thank you.

 

[TonyR68]

@mrsol ,

I followed the Pentair IntelliChem guidance for CYA for 2 seasons to manage the IntelliChlor based on ORP. FC was rarely right, almost always too high (12-15) or too low (0-2). I followed the guidance from the IntelliChem - Further Reading (sec 1.8 How To Disassociate Intellichlor & IntelliChem) setting CYA at about 70-80 and I’ve never looked back. IntelliChem is great for PH monitoring and dosing.

Tony