How Much Algae is OK?

saml

0
Jun 3, 2008
51
Near Knoxville TN
First, as I have eluded to in other posts, I have been a lost ball in high weeds trying to take care of our pool until I read up on the BBB method and other knowledgable facts of pools. I have finally reduce CYA from somewhere >180 to around 70-80, got PH to move up from stuck on 6.8 to a little on the red side of 7.5, TA is down from 180 to 110, and CH has dropped from 250 to around 220 which I think is OK for vinyl pools (Is it?). I have been trying to keep FC to the Pool Calculator min value for the respective CYA and am still learning the daily life cycle of our pool's chlorine usage which means it has dropped <min value. The CC is still 0 as of this morning. (All test done with my newly aquired TF-100 which is muuuuuuuuuuuch better than the strips.) None the less, I do see small areas (~3x6") of green algea apear in corners and along the vertical wall intersect with the angled hopper. I brush it away and a few days later here it is again. The pool is a little hazy and doesn't have that sparkle and shimmer I would like. However I can see the bottom very well which is much better than before I lowered my CYA level and got away from "pool chemicals" packed with stabilizer. I have read other articles that discussed some recurring algea like around steps, ladders, and other pooor circultion areas of the pool. Since I haven't shocked per the pool caculator guidelines since converting to BBB I thought maybe I should give it a blast, but then at my CYA levels that's a bunch of bleach. With all that said, what are the recommendations for this periodic algea appearance? If I do need to shock with bleach how high of a FC level can I go with a vinyl pool?

Thanks
 
CH is not an issue for vinyl pools, unless it gets very high. Your level of 220 is fine.

To answer the question in your subject line, NO algae is ok!!

You say you are keeping the min. FC and are seeing algae. For now you need to shock your pool according to the calculator (which is a safe level for ALL pools) and keep shocking until you can hold your FC overnight. Keep brushing.

You will obviously need to run your FC a little higher than the minimum, since that is not enough to keep your water clean!
 
I thought that would be the case. Do I increase FC to the Pool Calculator shock level each evening and check it each morning and keep doing that until it gets to where the PM and AM readings are the same? What is the proper technique for shocking? I've been trying to find it and figured it was easier to ask.

Thanks
 
Shocking:
1) Measure the FC level
2) Add chlorine to bring FC up to shock level
3) Repeat steps 1 and 2 as frequently as possible, as often as once per hour, and not less than twice a day, until the FC level remains the same overnight and CC is 0.5 or lower.
 
saml said:
Thanks for the quick reply. So should I wait till next weekend when I have all day to keep an eye on it and just keep sweeping through the week?

I wouldn't. Shock tomorrow night and check it again Tuesday morning. Shock it again Tuesday night, and check the levels again Wednesday morning. Twice a day is better than not at all and waiting a week.....

Good luck.
 
There are two approaches towards algae. If you have a major algae problem it is best to wait till you have enough time and all the materials on hand to mount a concentrated campaign against the algae. On the other hand, if you have a fairly minor algae problem, getting some extra chlorine in quickly can often dramatically reduce the total amount of work you need to do, least it become a major problem while you are waiting.
 
Good advice and I think it worked. One thing I found is that the Pool Calculator seemed to come up low for estimated bleach needed to obtain my shock value of 21 @ CYA 80 ( I think the CYA is lower than that but went conservatively to be sure.) None the less here's how it went for me (all bleach is Wal-Mart ultra 6%):
Monday evening. Added bleach & swept pool -FC 17.5 Added 2-174 oz jugs and went to bed.
Tue @ 05:20 FC 18 CC <.5 Added 1 - 174 oz jug and went to work.
Tue @ 19:00 FC 11 CC 0. Added 3-174 oz jugs. Swept pool to help mix. @21:00 FC 18.5. Added 1-174 oz jug. Swept to help mix. @ 21:45 FC 21.5 CC <.5
Wed @ 05:20 FC 17 CC 1.0. Added 1-174 oz jug and went to work.
Wed @ 19:30 FC 14 CC 0. Wised up, added 3, not 2-174 oz jugs. Swept pool to help mix. @ 20:50 FC 21.5 CC <.5. Ahhh right on the nose!
Thur @ 05:10 FC 21.5 CC <.5 YEA!
Thur @ 20:00 FC 14 CC 0. Did complete test - pH *7.6-7.7, TA 130, CH 130, CYA 60-70. (*pH on the red side of 7.5 but not to 7.8.)
Today (Fri) @ 07:00 FC 14, CC 0.

Looks like my shock worked? Water also look some clearer. Should I stay with the lower CH value for a vinyl pool? Also should I bring down the pH and TA?

Comments, thoughts, or recommendations?

Thanks
 
One thing I found is that the Pool Calculator seemed to come up low for estimated bleach needed to obtain my shock value

1. Bleach is low in strength
2. Time delay for testing (algae already consumed some bleach)
3. Your pool is larger than you think

I would suspect one of the above rather than the calculator.......I found some 4% bleach as a result :shock:
 

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Don't worry about PH or TA right now. The PH test is not accurate when you are at high FC levels. Wait to see what it is when FC is below 10. You only need to lower TA if it is causing problems.

CH at 130 in a vinyl pool is just fine.
 
saml said:
Good advice and I think it worked. One thing I found is that the Pool Calculator seemed to come up low for estimated bleach needed to obtain my shock value of 21 @ CYA 80 ( I think the CYA is lower than that but went conservatively to be sure.) None the less here's how it went for me (all bleach is Wal-Mart ultra 6%):
Monday evening. Added bleach & swept pool -FC 17.5 Added 2-174 oz jugs and went to bed.
Tue @ 05:20 FC 18 CC <.5 Added 1 - 174 oz jug and went to work.
Tue @ 19:00 FC 11 CC 0. Added 3-174 oz jugs. Swept pool to help mix. @21:00 FC 18.5. Added 1-174 oz jug. Swept to help mix. @ 21:45 FC 21.5 CC <.5
Wed @ 05:20 FC 17 CC 1.0. Added 1-174 oz jug and went to work.
Wed @ 19:30 FC 14 CC 0. Wised up, added 3, not 2-174 oz jugs. Swept pool to help mix. @ 20:50 FC 21.5 CC <.5. Ahhh right on the nose!
Thur @ 05:10 FC 21.5 CC <.5 YEA!
Thur @ 20:00 FC 14 CC 0. Did complete test - pH *7.6-7.7, TA 130, CH 130, CYA 60-70. (*pH on the red side of 7.5 but not to 7.8.)
Today (Fri) @ 07:00 FC 14, CC 0.

Looks like my shock worked? Water also look some clearer. Should I stay with the lower CH value for a vinyl pool? Also should I bring down the pH and TA?

Comments, thoughts, or recommendations?

Thanks

It looks like you're almost there. It can take some time for your filter to clear out the dead algae in the water, so keep your filter going 24/7, and keep your FC at the recommended level for your CYA. Ditto Duraleigh and Jason on the rest.

Congrats!
 
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