Green Algae

[Motordoctor]

Is green algae loose? Meaning the bottom of my pool is covered with green debris but it's not sticking, if you run a skimmer over, it moves easily. I shocked the pool last week with 4 bags of shock and am wondering if that green debris is dead algae or live. Thanks.

12x24x4 above ground pool so about 7500 gallons.

 

[jblizzle]

Likely alive. You need to follow the SLAM process described in Pool School. A few bags randomly added to the pool is not going to cut it.

 

[Motordoctor]

Will do. Pool, prepare to be SLAMmed

 

[Motordoctor]

Started the pool SLAM today, got a little carried away with the chlorine. The stuff must have been a little more potent then I thought. The pool calculator said I should add 3 gallons of 6% bleach to set the FC to 31. Put three gallons into the pool through the skimmer, let it sit for a couple of hours, then tested it. According to my kit, the FC is about 50 right now. I'm assuming that I just have to wait a couple of days for the level to come down to 31? Have the pump/sand filter running 24/7. Vacuumed all the green stuff off the bottom before I started the SLaM. Thanks for your help....

 

[pwrstrk]

Are you sure you have your pool volume correct and are you sure the bleach you used was 6% ? Just about all bleach now is 8.25%.
Just let the FC drift down.
What test kit are you using ?

 

[JVTrain]

Do you have the pump running 24/7 now? Needs to be done during SLAM. Also, don't pour bleach into skimmers. If you do, concentrated bleach goes right through your pump station and doing so regularly can shorten the lifespan of seals, o-rings and other pump/filter parts. Pour bleach slowly in front of a return jet to let it disperse evenly in the pool. Brushing the bottom and sides in the area around the return(s) you added near is a good idea too. No permanent damage done, just add differently going forward.

Test the FC again soon to see if it has dropped any due to better circulation or consumption by organics. Let it come down normally if still high.

Did you adjust pH before starting? Post test full test results from prior to starting SLAM if you can. The pH test unreliable at high FC levels, that's why pH should be adjusted first.

 

[pwrstrk]

If you could add all your pool and equipment info to your sig that will help us help you better. Then you won't have to type it in your posts. ?

 

[Motordoctor]

Sorry, I thought I had put the pool info in. It's a 12X24x3'6" for a total capacity of 6700 gallons. Above ground, actually partially in the ground about 3 Ft.
Starting numbers (TF100 kit)
FC=5
PH=7.5
TA=90
Calcium=300
CYA=80
C.C.=0
I used the store brand bleach which doesn't list the strength on it. The 6% I guess is a default setting on the pool math calculator. Even plugging in the numbers @ 8.25% doesn't give me the numbers I'm getting on the FC. Oh well, it should definitely kill whatever is in the pool though
The reason I put it in the skimmer was this: I think there's an algae buildup in the sand and I wanted to make sure it was dead. I vacuumed the pool a couple of times with some algae evident on the bottom of the pool with the filter on and I think it just went through the filter. When I backwashed the filter, when I put it on filter it was blowing the green stuff back in the pool from the return. This time I just vacuumed to waste although that really wastes some water. Here in NYC you get double charged for the water. The water charge plus a 118% sewer charge which more than doubles the cost of the water. Thanks again. I will check the FC tomorrow morning and see where it’s at from overnight.
When you close the pool, do you want the water at shock level? Last year I used a pool cover with the fine holes to let the water through that accumulates over the winter. Not a real good idea. The water looked like pea soup when I opened it this year. This year I’m going to use a solid cover with the perforated cover on top.

 

[pwrstrk]

I'm getting 2.2 jugs (121oz jugs) or 2 gallons 1 cup of 8.25% to raise your FC from 5 to 31.
If it was 6% I get 2 gallons 3 quarts to do the same. This is using 6700 gallons as you just stated above the volume is. What volume did you enter 6700 or 7500 ?
In the future don't buy bleach that doesn't list the precent of chlorine on it. Walmart's brand regular bleach is what I use.
Yes you want your pool at shock level when you close. The key is water temp. You want the water temp below 60 when you close and below 60 when you open. Low 50's would be great. ?

 

[Motordoctor]

I went back and checked the numbers. @ 6% which I guess is the default setting, it says to raise a 6700 gallon pool from 5 to 31 would take three 121 oz bottles or a total of 361oz. Thought maybe I was becoming dyslexic or something

Thanks for the tip on water temp. Have to get a thermometer, don't have one for the pool.