First test with TF100, order of operations for adjusting pool

[JimFinn]

Hey all! Finally got my TF100 in and ran my first test. Results are:

pH 7.5
FC .5
CYA 20-30
TA 80
CH 175

Attempted to do a Chlorine drop test but the FC was so low that it never turned pink. pH was done on a meter and the visual test. The pool has been on tablet use until last week, only liquid chlorine from here on out. Also, the water looks really good right now with no visible algae.

According to the charts, I should probably bring my CYA up to 45, by adding some stabilizer in a sock. Then I'll need to bring my FC up by adding LC. As for the calcium hardness, its low, does that seem normal? I performed the CH test by using the instructions in the kit, which were different than the instructions on the video.

What would you do, in which order?

 

[wireform]

Don't bring the cya up until you're sure all is right. Get the FC up asap with liquid chlorine

 

[ajw22]

We round CYA up. If the dot disappears between 30 and 20 we call it 30. The scale is logarithmic, not linear and you cannot measure a value like 45. Just round up. So your CYA is 30.

Target FC for CYA 30 is 4 to 6. Shoot for 6 and raise your FC.

Then do a Overnight Chlorine Loss Test and see if your water is really algae free.

Don't raise your CYA until you pass the Overnight Chlorine Loss Test

Once you get everything else within range you should work on raising your CH up around 250.

What is the pH, TA and CH of your fill water?

 

[JimFinn]

What is the pH, TA and CH of your fill water?

Good question. I'll be finding that out in the morning in addition to Overnight chlorine loss.

 

[JimFinn]

Another question I just thought of. Say I'm trying to bring my FC to 6, adding the correct amount of liquid chlorine according to pool math. When should I be retesting my FC after adding the chlorine?

 

[reggiehammond]

Another question I just thought of. Say I'm trying to bring my FC to 6, adding the correct amount of liquid chlorine according to pool math. When should I be retesting my FC after adding the chlorine?

30 minutes after is a safe bet

 

[ajw22]

When should I be retesting my FC after adding the chlorine?

30 minutes after adding the LC is fine for testing.

 

[JimFinn]

We round CYA up. If the dot disappears between 30 and 20 we call it 30. The scale is logarithmic, not linear and you cannot measure a value like 45. Just round up. So your CYA is 30.

Target FC for CYA 30 is 4 to 6. Shoot for 6 and raise your FC.

Then do a Overnight Chlorine Loss Test and see if your water is really algae free.

Don't raise your CYA until you pass the Overnight Chlorine Loss Test

Once you get everything else within range you should work on raising your CH up around 250.

What is the pH, TA and CH of your fill water?

My well water came in at:
pH 7.4
TA 150
CH 75

Performing chlorine loss test tonight

 

[JimFinn]

Overnight test: went from 5 to 3.

Slam?

 

[mknauss]

What does your water look like?

 

[JimFinn]

What does your water look like?

Beautiful. Clean and clear. No visible algae.

 

[mknauss]

Follow the FC/CYA Levels using the upper target limit for a few days. Then do another OCLT with your FC at upper target level to start.

 

[JimFinn]

Follow the FC/CYA Levels using the upper target limit for a few days. Then do another OCLT with your FC at upper target level to start.

Mr. Knauss, kind of a dumb question here. With FC level target ranges above 5, I’ll have to do the chlorine drop tests instead of using the OTO chamber to test my chlorine, correct? A lot of people do the drop test every day?

 

[mknauss]

You should do the drop test whenever you want to know the level of your FC. The OTO test is simply to indicate the presence of chlorine. Over time, you should be able to tell if the FC is above or below 5 ppm with it, but not much else precision.

 

[JimFinn]

Gotcha, makes sense. Should I start working on the CYA level and CH after these couple days at the FC upper limit?

 

[mknauss]

If your CYA is at or above 30 ppm, it is fine for this time of year.

The CH needs to be at or above 250 ppm.