Bad FC Test or not enough time for chlorine to dilute

[uneasyrider]

I'm a bit stumped. Backstory, waiting on my K-2006 for over 2 weeks, went ahead and ordered single DPD/FAS and CYA tests from TFTESTKITS. Arrived yesterday

Measured last night before starting SLAM today. FC was nil (I've had my SWG off bc I was draining/diluting to get my CYA down). CYA was 15

Per PoolMath, SLAM level is 10ppm. Advise to add 1 gal of 10% liquid chlorine. Which I did.

Waited about an hour and half and tested FC. Added 2 scoops of DPD. Started adding R-0003, and basically stopped once I hit 40ppm (80 drops). Thought maybe it didn't need 2 scoops of DPD, so I started over with just 1 scoop. Same thing. Stopped measuring at 50ppm (100 drops). The test water just isn't turning clear.

I wouldn't think that the reccomended amount of LC would chlorinate that much.

I backwashed before adding LC and pump is running nonstop.

If it matters, I also added 120lbs of salt about 2 hours before I added the LC. Could this be affecting it?

 

[ajw22]

Were you using a 10ml sample or a 25ml sample for testing?

 

[uneasyrider]

Were you using a 10ml sample or a 25ml sample for testing?

10ml

 

[Mdragger88]

That amount of 10% liquid chlorine should have increased fc by about 9ppm
Maybe you got some really potent chlorine?
Go test your tap water.
Also, are you letting the sample sit in between drops?
It should be about a drop per second
Swirling the entire time
Bottle completely vertical- only light pressure- don’t squeeze the bottle. Let the drops fall out.

 

[uneasyrider]

I'm an idiot. I was adding R-0003 for the FC test, instead of R-0871. Disregard this thread

 

[Mdragger88]

I'm an idiot. I was adding R-0003 for the FC test, instead of R-0871. Disregard this thread

Dang…. I was getting ready for a road trip to scoop up some 30% liquid chlorine lol

 

[Mdragger88]

P.s.
with less than 30ppm you will really be battling the sun along with your algae problem during the SLAM Process.
You may want to increase it a tad.

 

[uneasyrider]

P.s.
with less than 30ppm you will really be battling the sun along with your algae problem during the SLAM Process.
You may want to increase it a tad.

I thought about that as well. I was guesstimating on how much I was diluting my CYA and I got it a little low for my comfort. But I'm going by the FC/CYA SLAM level. Would it be bad to try and raise my CYA while in the middle of a SLAM?? I know I'll have to adjust my FC up, but apparently I need to do that anyway.

 

[mknauss]

Read the SLAM Process
Raise your CYA to 30 ppm.

 

[Mdragger88]

I thought about that as well. I was guesstimating on how much I was diluting my CYA and I got it a little low for my comfort. But I'm going by the FC/CYA SLAM level. Would it be bad to try and raise my CYA while in the middle of a SLAM?? I know I'll have to adjust my FC up, but apparently I need to do that anyway.

No - it isn’t bad- It is recommended to do slam with at least 30ppm cya - the corresponding fc level is 12ppm so not a huge jump. It will probably also use less chlorine in the end. The sweet spot is 30-40ppm cya for slam. Use the sock method for the cya & chlorinate accordingly.