Can't clear up algae before closing.

[Jennica]

Hi, pool experts!
I've been wanting to close my pool for a week now but can't get the algae to clear up in order to do so.

To make a short story long....

When I went on vacation I put a few pucks in the floater. When I came back, i measured the CYA and it read 30, so I added bleach accordingly. A few weeks later, I had algae. I retested the CYA and it was 50. I guess it took longer than a week for the actual CYA reading to be accurate because I hadn't added any more.

I've been slamming for days. The pool is no longer green but it is cloudy. CC is 0. I lose little to no FC overnight. It's been holding at 23 ppm for the last few days.

There is however, plenty of algae in the filter cartridge whenever I clean it. I take it out, hose it down, and soak it in bleach water before replacing it and running the filter again. Been running it night and day.

Do you think it might be a good idea to run the filter without the cartridge in it, so the bleach gets distributed but the algae doesn't collect in the cartridge? Or do I just need to be more patient with the slamming? Changing out the filter cartridge is no fun.

FC - 23
CC - 0
PH - 7.5
Alk - 125
CYA - 50
Borates - 50

Thank you !

 

[Texas Splash]

Well Jennica, according to your K-2006, you are now at the appropriate FC for a CYA of 50. That is true. Apparently the higher CYA during your vacation, which required that higher FC, wasn't achieved which is probably how you got the algae to begin with. A few basic items to verify as you continue to SLAM:
- What date did you actually start your SLAM?
- What type of bleach are you using, and what percentage strength is it (8.25%, 10%, etc)?
- Do you have anything in the pool (steps, ladder, light, etc)? Any of these are notorious for housing algae, so be vigilant.
- Have you been following all the SLAM steps "to the letter" on the Pool School - SLAM - Shock Level And Maintain page?
- Are you able to "maintain" that high FC all day, or does it fall during the day (i.e. going to work)?

I would not remove the cartridge. You need it to filter-out the dead algae. The filter wont remove or kill live algae, that's the bleach's job. Just make sure you hose it off at least once a day, maybe more if you need to. When you add bleach, is it able to circulate around your pool okay? Some people don't have many return jets, so you may need to help it around with a brush. Besides that, stick with it. Bleach is a great sanitizer, and it will kill the algae if it is maintained at the right level all the time. The only other thing .... just make sure your CYA is still 50 and not higher. If it was higher, then your FC would also need to be higher.

Hang in there!

- - - Updated - - -

Oh, and during your SLAM, there's no need to test for anything else right now other than FC and CC. You can check CYA one more time just to be sure it's 50. All the others can wait until after the SLAM is done.

 

[Jennica]

I started the Slam on Monday, so it's been 3 days.
I'm using Clorox 8.25, nice and fresh.
The only thing in the pool is the removeable steps.
Since I started Slamming, the FC has held pretty steady. I've hardly even had to add much bleach.

***Just went out to pull the ladder out and indeed there was some algae on the steps.

Guess I'm back to Slamming!
Thanks for the suggestion. Will post an update later.

 

[Texas Splash]

Those ladders are notorious for algae. Good you got them out. Also, you may save a few $$ if your local store has generic (regular) bleach. It doesn't have to be a brand name. 3 days is still fairly early for a SLAM, so just hang in there. We'll watch for your update.

 

[Jennica]

Thanks!

 

[domct203]

There are three criteria that needs to met to complete a SLAM:

1) Ability to pass an OCLT
2) CC is 0.5ppm or less
3) The pool is clear of any algae, living or dead.

You do not have a clear pool so the SLAM must be maintained.

I find it odd that you are passing the OCLT with visible algae. Are you brushing daily?

Dom

 

[Catanzaro]

A few weeks later, I had algae.

Since I started Slamming, the FC has held pretty steady. I've hardly even had to add much bleach

Q: Is the whole pool full of algae, or just some spots?
Q: If you have algae, your FC should not be holding steady. Under normal conditions, you could lose 2 ppm per day. The weather is cooler, so chances that you would lose less, more like 1 ppm daily.

As Texas Splash and Dom mention, please follow the SLAM procedures to a T. If your water is clear, and your CC is 0, I would perform the overnight test. If you pass the test, attempt the overnight the following evening, and then you should be all set. The pool will go from green, to cloudy and hazy, and then to clear and a few days later, crystal clear. I read somewhere you could register CC of 0 and still have algae (just can not put my finger on it).