Best way to prevent mustard algae?

[swchoi]

Should/Would algaecide PQ60 or yellowout work???

I had a house with a pool that and started maintaining last year and this year.
What I finally figure out by reading lots of posts and what I experience from last year and this year is I had mustard algae.
This time, I had mustard algae when I am maintaining FC @ 6-8 and CYA @ 40. I bought the TF-100 test kit this year.
I shock it to a bit over 20ppm of chlorine and I am seeing it growing more and getting cloudier over 3 days even with brushing and vacuuming.
and then I read more and finally realize it is mustard algae, I then shock it to 30ppm, but end it up with 43ppm with the test kit.
(not sure why, I used the pool calculator. but not important now)
run the filter and the water is crystal clear after about 36 hours.
but the problem is every time I shock to such a high level, I loose swim time at least a few days and it is always the prime times for swimming here in MA.
and this week and the next, the temp is around 90 and I am loosing swim time for at least a few days.
I just feel I am doing all this work for very little swim time..
I also added borax (probably about 20ppm. I know it should be at least 30ppm, but I don't want to to do until I have a test strips) to the pool now and hope it helps to prevent it.

I also see some green stuff on my garage roof, I wonder if that is where it is coming from, if so how do I get rid of that?
would putting PQ60 for maintenance work to prevent it?
or should I use yellowout when it happen be better?

 

[Texas Splash]

I've seen tis type of question several times, and inevitably the same answer is this, "If a pool is maintained with the proper amount of chlorine (FC) based on it's current CYA (stabilizer), it will be void of algae." That hold true regardless of the many, many types of algae out there. The problem is that we as pool owners missed the mark somewhere. Here are some examples:
- CYA tested was too low; should actually be higher. This means the SLAM/Shock FC value being applied is too low
- SLAM terminated before all 3 criteria are achieved (very popular).
- Mustard algae actually turned-out to be pollen, dust, or some other product
- Poor circulation

Not trying to discount what you are seeing, just letting you know there are variables that may be in play here. I would suggest you post a full set of numbers with your TF-100, and don't put anything else in your pool right now other than liquid chorine so we have a chance to validate what needs to be done first. Hope this helps.

 

[swchoi]

I haven't added anything other than maintain the chlorine level.
it's been almost 2 weeks, the water is still crystal clear. (and skipped filtering for more than 2 days due to vacation too)
I am pretty sure I did something wrong before this SLAM.
like the algae is probably not all killed from last season since I had problems all season last year because I never SLAM to the mustard algae level, etc...

Well, I visited 2 hotels' swimming pool during last week's vacation and only now I realized how cloudy the hotel's pool water is.
they are hyatt and residence inn pool by Marriott(small pools). didn't really want to swim in it now that I know more about pool water and how clear it should be.

 

[Divin Dave]

First, you HAVE to be rid of all the algae. So many people stop the slam before its truly all killed and then it comes back.
After getting rid of the algae by proper slamming. Then maintain FC / CYA relationship and brush the pool weekly. Its really that simple.

If your target in pool math was 30, but you ended up with 45FC, then either your pool size isnt what you think it is, or you added more chlorine than what you think you did.