Excessive Chlorine Usage (5 to 6 ppm per day)

[proavia]

Don't "strain" to see it. Hold the tube at waist level, back to the sun, just glance into the tube, then look awayand glance at the tube again. If you can see the dot at 50 and can't see it at 40, use 50 foryour CYA reading... always round CYA up.

 

[Texas Splash]

Just noticed light green spots on the stairs

That's never good. Visible signs of algae would be a need to SLAM. But at least it explains the FC drop.

 

[Texas Splash]

As Gene noted, no need to strain for the dot. Some people like to squirt a little solution in the viewing tube, look away, then look back. I'll pour the solution back into the mixing bottle and do the test 2-3 times if I need to or ask someone else for their opinion.

 

[newbie2017]

I am surprised that we passed OCLT.

To be on the the safer side, going to consider a CYA of 50 (most likely 40) and bring Chlorine to 20.

Anything else, I am missing?

Thanks a bunch to everyone.

 

[newbie2017]

I am now wondering if we did a proper SLAM the first time around. We brought it to shock level and the pump ran continuously for 2 days. Water cleared up. Did not test until the water cleared out. Passed OCLT.

Should we be testing a few hours after bringing to shock level and bring it up shock level again? How long should we keep it at shock level now, given that the pool is clear?

Thanks.

 

[IceShadow]

I am now wondering if we did a proper SLAM the first time around. We brought it to shock level and the pump ran continuously for 2 days. Water cleared up. Did not test until the water cleared out. Passed OCLT.

Should we be testing a few hours after bringing to shock level and bring it up shock level again? How long should we keep it at shock level now, given that the pool is clear?

Thanks.

You are correct - you need to test often (every few hours is ideal, minimum 2-3 times daily) and bring the FC back up to level when you do. You do it until there’s no sign of algae at all, pass OCLT, CC at 0.5 or less.

 

[mknauss]

Read the SLAM Process. M is for Maintain. You test FC and add liquid chlorine every few hours. The three criteria for a successful SLAM are in the article.

 

[newbie2017]

Day 2 of SLAM. FC has been at 20 and did 3 additions yesterday and 3 today. There was a drop of 5 ppm between the tests today. A bad time for the speed stir to stop working
. Doing the test with 5ml sample for now.

Water was crystal clear to begin with. I haven't done the OCLT yet, because I am still registering CC. It was 1.5 this afternoon and 1 in the evening and night. This concerns me. Any reason why that could be? Had a 0.5 CC prior to starting SLAM.

Thanks.

 

[mknauss]

CC is typically the result of active chlorine consuming organics. UV on the pool surface will eliminate CC.

 

[newbie2017]

CC is typically the result of active chlorine consuming organics. UV on the pool surface will eliminate CC.

Thanks. I am assuming, I should continue SLAM until CC is at .5 and then do OCLT. Is this right?

 

[mknauss]

The three criteria for a successful SLAM are in the article.

As stated in the SLAM Process article, first is crystal clear water, then pass OCLT with 0.5 ppm CC or less.

 

[newbie2017]

First SLAM ever.. Pool has been at shock level the past 3 days. Crystal clear water, no visible algae,, brushed Monday and Tuesday but was getting a CC of 1. First OCLT last night.

Last night. FC. 17, CC 1
Morning. FC. 19, CC 1

I did it twice this morning and it was 19. User error is the only reason I can think of, for the reading at night

Now, the CC. We barely had sunlight the last two days. Could that be a reason why the CC is still lurking? No sun in forecast for the next few days as well.

Pump has been running non stop as well. (Getting expensive, and not seeing an end
)

Should I continue to keep it at shock level? Will the CC clear with no sun?

Thanks.

 

[mknauss]

If you have no debris build up in the pool, you can return your pump to its normal schedule.

Clean your chlorine testing vial with bleach or rubbing alcohol. We have found that persistent CC can be traced to dirty testing vials.

 

[newbie2017]

If you have no debris build up in the pool, you can return your pump to its normal schedule.

Clean your chlorine testing vial with bleach or rubbing alcohol. We have found that persistent CC can be traced to dirty testing vials.

Thank you. Should I let chlorine levels drift down?

 

[mknauss]

That is up to you. I would first clean all my testing equipment really well and then test again.

 

[newbie2017]

That is up to you. I would first clean all my testing equipment really well and then test again.

Thanks. Will CC usually clear with no sun? Just trying to understand. Will search the forum/school as well.

 

[mknauss]

Even cloudy weather has some UV penetration. So yes, the CC should clear.

 

[newbie2017]

SLAM novice. Sorry for the many questions.

If I am already registering a CC > 0.5 at night, is there any point in doing OCLT since one of the slam criteria will fail anyway? (I am assuming CC is not going to go away at night.)

 

[mknauss]

Another day at SLAM level FC will not hurt. So if you cannot get a lower CC, no need to do the OCLT.

On the other hand, if you pass multiple OCLT, we suggest you let your FC come down to 10 ppm or so and then do a CC test. Elevated FC testing does have some errors.

 

[Rboss]

Can I ask what is OCLT.