Overnight chlorine test results and SWCG productivity test

[BB_Mike]

I am about to jump into the TFP method of higher CYA and higher FC content in my pool. I have already adopted most of the other simple/BBB principles in my few years of owning a 500 gallon spa. For my pool, before I put in anything going forward, I want to know if my pool is ready for it and has a good starting base. So I did an overnight chlorine test and also a baseline SWCG output test.

Intex above ground 8500 Gallon pool. Water looks great. During this test, I left the pool covered with the manufacturers plastic cover that has 4 small one inch holes on the outer edge. Weather was partly sunny with a high of 88* and and overnight low of about 68*.

Taylor test kit 2106 (bromine for spa) that I have added to with the chlorine agents and CYA. I am confident in all measurements accept CYA. Dang that black dot I see it in my sleep even...

Thursday 8:00am
FC = 5.00ppm
CC = 0.2 or less.
CYA = 30ppm (This is from my pool store. I still struggle at doing this test for the smaller numbers of CYA)
I then ran the SWCG and pump/filter for 8 hours until 2pm.

Thursday 8:00pm
FC = 6.0ppm
This equates to 1ppm for 8 hours of running. Disclaimer being I waited 7 hours afterward to pull the water, but the pool was covered. The cell supposedly produces 11gr/Hr. Does that math add up for 8500 Gallons? Salt level is 3000ppm.

Friday 8:00am
FC = 5.4ppm
CC = 0.2ppm or less.
TA = 80ppm
CH = less than 50. Fresh fill with tap water 3 weeks ago for a vinyl pool. This low CH allows me to add Cal Hypo for a SLAM, right?
PH = 7.8 I plan to bring it down first before anything else, right?
CYA = 30

My pool company uses the Taylor Xpress Flex machine and I rely on them for CYA.

So where should I go from here? My desire is to go to a CYA of 50 and try that out until I close the pool, then go higher next year.
Is a ~0.6ppm FC drop over night while covered worthy of a SLAM? If so, how much Cal hypo (73%) should I put in to SLAM it up to FC of 12ppm.?
I also have on the ready: cyanuric acid granules, Pool Essential liquid bleach (4 pack for $18). Will this bleach store well over winter in a garage?

I plan to raise the calcium eventually, before I close the pool and use up this cal hypo.
I plan to order the 50ppm CYA sample and get good at that. For CYA to be the linch pin of the TFP method, it's a fairly subjective test method, but I probably thought that about PH shades of red many years ago.
Ok lots of hidden questions in there. Sorry and thanks for all of your help.

 

[ajw22]

You don't need to SLAM your pool.

Add the CYA, crank up your SWG, and monitor the FC level and see how it goes.

You don't have to hit precise numbers. Anywhere in the ranges is good enough.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

Stored bleach will degrade over time....

Breakdown of Bleach Over Time by Storage Temp - Further Reading

www.troublefreepool.com

 

[randytsuch]

What test are you using for FC/CC?
Not sure how you can get numbers like .6 and .2 ppm?

The FAS test normally gives you 0.5 ppm resolution.

 

[BB_Mike]

I cannot crank up my SWCG. It is either on or off.

My bleach bottles came from home depot, stored outside in the shade. We've had some 100* days over the past month. Is there a method for testing FC using my taylor kit? so that I can baseline the whole lot of 4 jugs?

 

[ajw22]

The FAS test normally gives you 0.5 ppm resolution.

0.5 resolution with a 10 ml sample

0.2 resolution with a 25 ml sample

I assume the OP is doing the test with a 25 ml sample.

 

[BB_Mike]

What test are you using for FC/CC?
Not sure how you can get numbers like .6 and .2 ppm?

The FAS test normally gives you 0.5 ppm resolution.

My Taylor kit has the option to put in 25ml of sample liquid, which gives a finer resolution of 0.2ppm per drop of R-0871. To that end, I using the bigger bottles of that stuff. I can also use the 10ml sample and get .5 increments. I wanted to be precise for this though.

 

[ajw22]

My bleach bottles came from home depot, stored outside in the shade. We've had some 100* days over the past month. Is there a method for testing FC using my taylor kit? so that I can baseline the whole lot of 4 jugs?

That is often a problem.

Just calculate what the expected rise for the chlorine added using PoolMath.

Then test the FC rise 15 minutes after adding into the pool.

You can then back into the likely % using PoolMath for the actual results you got.

 

[jmastron]

The 2 tests you did showed that you lost 0.6ppm FC overnight (which is probably okay), and gained 1ppm more than the sun consumed during the day.

To isolate and confirm the cell's productivity, you can do one more test -- an overnight test with the SWCG on 100% (8pm to 8am or whatever hours). The test results at the beginning and the end of that will tell you how much the cell generates.

 

[BB_Mike]

The 2 tests you did showed that you lost 0.6ppm FC overnight (which is probably okay), and gained 1ppm more than the sun consumed during the day.

To isolate and confirm the cell's productivity, you can do one more test -- an overnight test with the SWCG on 100% (8pm to 8am or whatever hours). The test results at the beginning and the end of that will tell you how much the cell generates.

ok, will do. I was hoping that the pool cover would negate the sun's UV effects. But maybe just loss from heat is a thing. Either way, producing 1 ppm in 8 hours covered is pretty sad, no? I see a lot of supplemental chlorinating in my future because running this pump for 12+ hours a day is going to eat up the electric bill. The intex krystal clear SWCG has a "boost" method that runs the system for 36+ hours. I used that a few times, and during a hot sunny day I saw only a .5ppm increase and thought it was broken.