Back again, algae that is

[Wes45]

I've been following the BBB rules and everything was fine until yesterday. I went out to the pool after a rainstorm and found this algae. Assuming it's mustard algae as my CL level has never gone below 4 since solving my initial problem a few months back. I'm shocking at Cl = 29 and checking it every couple of hours.
Can anyone confirm this is mustard algae? I posted over under "Everything else" because the only other place it might be hiding is behind my light fixture.
Just figured out how to post a picture,too. [attachment=0:2wafj6mw]Pool Algae post4.jpg[/attachment:2wafj6mw]

 

[reebok]

the yellow stuff I had was like dust or dirt that settled on the bottom and got stirred up when you would swim or brush. yours looks like the green algae I would get that grew on the walls. I only had a big green pool once or twice, but I had green algae on the walls with a clear pool a lot of times. and that's what yours looks like to me. the chlorine/cya chart is the magic formula, but are you also sure that you're getting good filtration, good circulation and brushing? it looks to me like that spot (or one of them) is below a return jet, so maybe it's not getting good circulation? fc dead spots in other words.

 

[Wes45]

Well, I'd be happy if it was green instead of yellow, althugh I've already kept the Cl at 29 for the past 24 hrs. I'm not real consistant at brushing the pool, does that contribute to algae growing? I thought if I kept me Cl between 4-6 I'd be ok if I got a little slack on the brushing. I'm running my filter 9 1/2 hrs a day, pretty much all the time the sun is on the water. Was wondering if I should increase that by an hour or so? Just learned that I can remove my light and clean behind there, too but can't do that now while the Cl is at 29.
I'm about ready to run out of the R-0871 liquid, too. Sure go through a lot of that when you are testing CL levels near 30

 

[frustratedpoolmom]

Ya gotta brush....

If the FC was too low for any extended period it can take hold...It does seem to indicate Mustard Algae based on your details... Did you check behind the light yet?

Pool toys, floats, etc., swimsuits, towels etc., all must be treated.

Have you verified the CYA level in the last couple of weeks?

 

[Wes45]

With the Cl at 30 I didn't think I should get in the water so maybe I'm wasting my time trying to shock it without cleaning back there? I lost 4 ppm again last night, from 30 to 26 so will try to keep it at 30 with 100 degree days and blazing sunshine all week, not sure if I should just let it drop back to 4 and clean out the light and start over. What do you think? I'm already up to 10 bottles of clorox so far.

Oh, and I better test the CYA again, can I do that accurately with the high level of CL?

 

[reebok]

yes you can test cya. this looks and sounds exactly like fc dead spot (no brushing, bad boy) green algae to me, but you gotta do what you think is best and right. I used to get the same thing to the side of one of my returns.
depends on your cya level and comfort level as far as getting into the water.
this whole dropping to 4 thing sounds like you still believe the pool industry or think you have 0 cya. up to shock level for your cya is fine, unless the cya is 0.

 

[Wes45]

I was referring to my normal Cl levels per this forum, with CYA of 50, I was keeping it between 4 and 6. Is that incorrect?

 

[PaulR]

For CYA 50, the chart suggests absolute minimum of 4 and preferred target 6. As I see it, that is your daily evening goal before adding any chlorine.

reebok is saying many people on the forum are okay with getting in water up to normal shock level, which for CYA 50 is FC 20. You don't need to let FC drop to 4, just to 20, to get in and scrub the light.

(And I have to say the pics look like green algae to me too; but I've never seen mustard up close and personal.)

And brush.
--paulr

 

[Beez]

I was referring to my normal Cl levels per this forum, with CYA of 50, I was keeping it between 4 and 6. Is that incorrect?

Well, FWIW, my CYA is at 55 and I run my pool about like you do, although I rarely let my FC drop to 4. I seldom brush and I don't have algae problems. Sounds to me like maybe you have a lingering problem from your last bloom and maybe got a little lax with your FC levels?

 

[Wes45]

Thanks for all the replies. I let my Cl level drop to green algae shock level for the last 24 hrs and it held last night at 16.5 and water is back to sparkly so it must have been green algae.
Lessons learned from the good folks here during round 2 with green algae:
I need to be more diligent in brushing - at least once weekly.
I need to check my CYA level more often, I just assumed since I was using bleach it didn't have to be retested for a long time.
I need to increase my Cl level a bit more, I will shoot for an evening level of 7 instead of 6 so it doesn't drop below 5 during the day. There were a few days in the past month when it had dropped to 3.5 after 105 degrees and blazing sun.
I need to get more R 0871. I have to do the drop test every day to maintain these levels.
I have to clean behind my light, never realized that was a maintenance area.

Hopefully this will keep my pool troublefree.