First post! (CH question)

BigMike0612

Member
May 5, 2025
9
Clearwater, FL
Pool Size
15000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello! First of all, thank you TFP for existing. I bought my current house last summer without knowing anything about pools, but I've slowly learned more and more about my pool (frustrating and expensive at times), and now I'm ready to fire my pool company and take things over completely thanks to Pool school and the pool math app.

I purchased the TF-100 a couple weeks ago and am testing regularly (couldn't recommend the smart stir enough). I called my pool company and spoke to a supervisor this week to get an idea of what they're doing to my pool....And it was not TFP standards — that's for sure. The guy straight up told me that FC and CYA have no relationship and that in the Central Florida summer, they want my CYA high (up around 100) with a FC of 3-5. Again, I was speechless.

My pool guy just threw in tablets into the floater for a while. My CYA is so Dang high. I'm keeping my FC high in the meantime (based on the TFP chart) — I haven't drained any of my pool yet.

Tests from today (Central Florida, 15k gallon plaster)
FC: 5
CC: None
PH: 7.5
CYA: 90
TA: 60
CH: 275

Main reason for my post is about the CH test. See images below. It barely turned pink/red. It made it difficult to do the CH test, but my estimate is that it was around 275 (hard to tell when it turned blue because it was so faint)...Is this normal? Do I need to add calcium chloride?

(First image is it not being mixed, second image is with the smart stir on.)

Screenshot 2025-05-17 at 5.34.15 PM.png
Screenshot 2025-05-17 at 5.34.28 PM.png
 
they want my CYA high (up around 100) with a FC of 3-5.
Nooooooooooooooo!
FC: 5
CYA: 90
Your FC is too low for your CYA. You need to be near the top of the range when you test. If you have to dose higher than range, so you are in range when you test, do that. Always follow this. Link-->FC/CYA Levels
Main reason for my post is about the CH test
250 is just fine for CH.
However, something is not right with your test.
Print the CH instruction below out, and follow it. Make sure you are using the correct reagents:
 
Welcome to TFP Big Mike!

The video below shows the test with a 25 mL sample, but you continue with the 10 mL sample. This will give you an idea of what color changes you are looking for. Towards the end of the test, continue dropping until you see no additional color change. Then subtract that last drop that made no change.


Good luck,

Regular-size Mike
 
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Nooooooooooooooo!

Your FC is too low for your CYA. You need to be near the top of the range when you test. If you have to dose higher than range, so you are in range when you test, do that. Always follow this. Link-->FC/CYA Levels

250 is just fine for CH.
However, something is not right with your test.
Print the CH instruction below out, and follow it. Make sure you are using the correct reagents:
Thank you! Yes I'm increasing my FC to match the CYA per the TFP chart.

I will do the CH test again tomorrow :)
 
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Welcome to TFP Big Mike!

The video below shows the test with a 25 mL sample, but you continue with the 10 mL sample. This will give you an idea of what color changes you are looking for. Towards the end of the test, continue dropping until you see no additional color change. Then subtract that last drop that made no change.


Good luck,

Regular-size Mike
Thanks!
 
Nooooooooooooooo!

Your FC is too low for your CYA. You need to be near the top of the range when you test. If you have to dose higher than range, so you are in range when you test, do that. Always follow this. Link-->FC/CYA Levels

250 is just fine for CH.
However, something is not right with your test.
Print the CH instruction below out, and follow it. Make sure you are using the correct reagents:
I tested CH again (twice) and it came out to 225 this time. So I'm going to buy some Calcium Chloride and get that up to around 300.
 
There is no need to raise it to 350, 250 is just fine.

I would test your fill water for TA and CH.
I'm at 225 though so I'd like to get it closer to 300 so I don't have to worry about it for a while.

I might drain some of my pool to get my CYA down though. It's at like 90. It's slightly inconvenient to put so much chlorine in to meet the chart's standards

Good idea on testing my hose water
 
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I'm at 225 though so I'd like to get it closer to 300 so I don't have to worry about it for a while.
Yeah. You get stoopid rain totals this time of year and would benefit from aiming high. Your CYA will come down similar on its own.
It's slightly inconvenient to put so much chlorine in to meet the chart's standards
For the most part, its only the initial add and from then on you're just maintaining +3 (etc) per day. Maybe you lose a hair more with an elevated FC to match the 90 CYA, but it won't break the bank for two months.
 
Yeah. You get stoopid rain totals this time of year and would benefit from aiming high. Your CYA will come down similar on its own.

For the most part, its only the initial add and from then on you're just maintaining +3 (etc) per day. Maybe you lose a hair more with an elevated FC to match the 90 CYA, but it won't break the bank for two months.
So you wouldn't recommend draining? Because I'd prefer not to drain
 
If you had a SWG, you might target 90 CYA once your UV is intense. Many in hot climates do.

It would be a rough SLAM if needed, so don't slack and need to go there. Or drain then if so.
 
If you had a SWG, you might target 90 CYA once your UV is intense. Many in hot climates do.

It would be a rough SLAM if needed, so don't slack and need to go there. Or drain then if so.
No SWG. I'll just keep my FC around a 7-9. I just fired my pool guy this week, and he was keeping it around a 4-5 and the pool has been okay for the past year I've been here.

But as I explained to my wife, just because the water is clear, doesn't mean everything is okay. It's just like me — I eat like garbage and I'm still alive, but that doesn't mean I'm healthy. Lol
 
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I'll just keep my FC around a 7-9.
You need to remain free and clear above min for your CYA. If youre losing 3 FC a day for example, you need :

Min
+ 3 FC
+ 1 or 2 FC wiggle room
---------------------------
= TFP clear.

lc_chart.jpg


As the UV gets insane soon, you may be dosing over target range to remain above min.
 
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