SLAM question re FC usage

[willy17]

Hi!
Working through a slam, in my third day. After some of the readings I was getting yesterday I was thinking the OCLT would go a bit better but this morning wasn’t great. 4ppm loss. In retrospect I should have re-tested but I added chlorine right away before so I’ll try again tomorrow. Had a couple stretches without loss last night before bed so I’m getting there (I hope). POP right? I’m scrubbing, using the robot, and pulled lights out and scrubbed there too. Yet to see any algae. Pool is crystal clear still. I’m testing in pretty much 2 hour increments even through the night day 1. Pool gets a very hot full sun (will actually raise temp thru the day quite a lot as it’s only 3.5-4 feet deep. Hoping this is why I get a high use of FC.
QUESTIONS (finally thanks if you’re still reading)
1 - is it normal to have a higher overnight loss than the night I decided to actually SLAM (lost 2.5 last week overnight last night I lost 4ppm or a touch more)?
2 - will FC be used constantly, like straight line type deal or are there peaks and valleys?
3 - would my usage be higher when my fc is in slam range or would it be the same if I had 5ppm in my pool?

Thanks in advance for your help or thoughts! I don’t know my usage per day but will find that out when this is done. My plan was to track it through day when I come off slam.
Cheers all! Being in southern Ontario (with brutal spring) I want to get this thing back in order and have the family in over this short season!

Ok I’ll stop now and look forward to responses.

 

[jblizzle]

1. It's possible, depends on what is being broken down in the water.
2. Again depends what is breaking down and of course the sun will cause increased losses.
3. The higher the FC relative to your CYA, the more FC that will be lost to the sun. I think you are also more likely to have higher losses in the OCLT which was designed to be done at the shock level, than if your FC was lower.

 

[willy17]

I’m in slam at 28ppm. I’ve been using the 5ml for 1 ppm so far.
For the overnight test, should I stick with the 5ml 1 drop = 1 ppm or should I shift to 10ml or more. I just did a test, was at 26/27ppm will adjust to get back to 28ppm and then test again before bed. I did a CC test here. 1 drop more than handled it so I think safe to say I am under .5ppm CC.

 

[jblizzle]

Use 10ml for the OCLT

 

[willy17]

had packed it in before I got message about using the 10ml.
I’ll get another crack at it tonight though as I unfortunately lost 3ppm. Pump pressure has stayed down, water clear, pretty much 0 CC.