Mustard be gone!

[CMS_Sprint]

It all started when I made the mistake of thinking there was just a lot of pollen in the pool ( It wasn't)

Water was clear but FC levels started to drop and I thought I had a cell problem (Again, it wasn't)

I tried to run the cell at 100% for a few days and was unable to make a rise in FC levels (my goodness I can be a slow learner!)

After reading all the info I could find on SLAM/Mustard Slam, I started that process on Friday.
Started with
FC 0
CYA 60
PH 7.2
Ca 350
TA 75
Temp 84

I raised FC to 24 for 24 hours and then took it to 36 for another 24 hours. Did the ODPD test last night/this morning and it fell to 32 overnight which is indicates that the little yellow brats are still hungry and still with me!

I'll add some more liquid chlorine this morning but won't be able to watch it as its a workday, but I'm going to presume that at these FC levels that close monitoring is less of an issue?

Once I pass the ODPD test, what's the recommended way to get the FC level down again? Just leave the SCG off until it falls?

Also I'm going to recommend that anyone with a SWG system do a ODPD test before they think the cell is failing, it would have saved me a ton of time!

 

[Texas Splash]

CMS, we probably should clear-up a couple things to avoid confusion. I am assuming by ODPD you are referring to the Overnight Chlorine Loss Test. That is one of the 3 passing criteria for passing a SLAM Process. Now if you believe you have algae and have failed an Overnight Chlorine Loss Test, then you perform a regular SLAM Process first - your required FC being 24. That will take longer than 24 hours. It might take a couple days, it may take a week. Depends on the amount of algae and time you are available to work on the pool. Only after you complete the regular SLAM do you increase the FC to the Mustard Algae level, and when you do it's only for 24 hours. We encourage using regular bleach to maintain the elevated FC level as SWGs simply aren't designed to do so.

Once you complete a SLAM, you can leave the SWG off or on a low setting until the FC falls back to range as noted on the FC/CYA Levels. Also note that once you complete the SLAM, your CYA should be 70 minimum.

 

[CMS_Sprint]

Texas Splash, thanks for the super fast response!

I guess I jumped the gun on raising the levels to mustard slam...I'll continue to slam until I pass the overnight chlorine loss test then do the "nuclear slam" to make sure the mustard gets knocked off.

Since I rushed the gun and the pool is at FC 32 now, I'll hold it there until the overnight test comes back OK.

I've also been running my robot vacuum as well as brushing as that seemed to be a good way to make sure all the equipment disinfected as well.

Having FC levels that high burns through the R0871 pretty quick, just ordered some more...

 

[Texas Splash]

Copy that. Also understand that exceptionally high FC levels usually tend to drop a little quicker than our standard target zone FC levels simply because there isn't enough CYA protection. So don't be surprised if the FC does drop a bit. If you're almost out of R-0871 drops, you can switch to the 5ML water sample size so that each drop equals 1 FC. It's not as accurate as the 10 ML sample and dividing that answer by 2, but it helps to save reagent.

 

[CMS_Sprint]

If you're almost out of R-0871 drops, you can switch to the 5ML water sample size so that each drop equals 1 FC. It's not as accurate as the 10 ML sample and dividing that answer by 2, but it helps to save reagent.

Thanks for the reagent saver tip, I'll use that until the new stuff arrives (hopefully) tomorrow...

Update:
FC fell from 25 to 20-21 over night (Is that what you meant by "a bit"?). Tested CA as well it's now at 40. Water has been crystal clear for the last 5 days (and wasn't really murky to begin with, but it's clearer now) No dust accumulating so I can presume I'm making some progress. There was no sunlight on the pool, I sampled at 9pm and 6am (dark to dark).

Questions:
1. Do I boost CYA back up to give the FC a chance to make it through the day or do I just adjust the slam level to match the current CYA
2. Does a FC drop from 25 to 21 indicate active algae or is this a normal drop at these levels?
3. Commence MA (nuclear) SLAM?

 

[Texas Splash]

Good morning! No need to boost the FC up past 16 now that your CYA is 40. We simply make that adjustment. The FC drop does still indicate something is in the water somewhere. Either transparent and suspended (hence the slight cloudiness) or perhaps growing in a hidden/undiscovered area. I would continue with the normal SLAM (CYA 40/FC 16) until you pass those 3 criteria. Now is a great time to really be crirital in the pool inspecting. If you have hollow steps, rails, or a light with a niche behind it, all those need to be inspected.

 

[CMS_Sprint]

Splash, thanks for your continued help!

Just to be clear, the target FC drop is alway less than 1, regardless of FC level? From a percentage viewpoint, I'm struggling with this a little.

In regards to the lights: I took them out as far as they would come and scrubbed them but obviously there's a lot of standing water in those tubes that I can't access....Any tips to clean light tubes?

 

[Texas Splash]

Just to be clear, the target FC drop is alway less than 1, regardless of FC level?

That's correct. In the grand scheme of things, when an FC is exceptionally low, or exceptionally high, our scientist math wizards agree there can be some minor variances, but that extreme. When we follow the general SLAM levels that are matched against a current CYA noted on the FC/CYA Levels, the 1 ppm drop of FC is the acceptable standard.

Are your lights the larger ones with the niche behind them? If so, about all you can do is clean out that empty cavity and perhaps leave it exposed (light on the deck if possible) for chlorine to attack any spores. If you only have the smaller 3" LED type fixtures, those don't need to be removed. Not much we can do about the electrical lines really unless you want try to inject some bleach in there with a syringe or turkey baster.

 

[CMS_Sprint]

If you only have the smaller 3" LED type fixtures, those don't need to be removed. Not much we can do about the electrical lines really unless you want try to inject some bleach in there with a syringe or turkey baster.

I like it! I have a few 100cc syringes at work...I'll rig one up with a tube and take the fight to the trenches!

Thanks again!

 

[CMS_Sprint]

Just a quick update on this. I had to travel for work last week, so wasn't able to monitor SLAM. My wife kept an eye on the CL level, which remained high, but not SLAM high. Thankfully all the CL had taken its toll on the CYA so I wasn't having to use as much liquid CL as in the past.

Last night the OCLT came back clear...21 Last night, 21 this morning! Happy days!

I've added another 2 gals of 10% CL and brushed like a mad man, so hopefully this is the end....

I've left the SWG off and will for a few days until the CL drops to a more sensible level. My plan is to wait until the CL gets to about 10 and then get my CYA back up to 70 and then turn the SWG back up on at it's usual level and monitor CL levels daily until it's back in the "happy zone"

One last question: What's a safe CL level for swimming? I miss it!

Thanks again to all for the help and advice.