Green Algae

dmalin

Member
Sep 7, 2010
5
Central Florida
Topic Split off by moderator

A week ago I notice what looked like dirt in the bottom of the deep end of the pool. Closer investigation led me to believe it was pollen. I ran the vaccuum and cleaned the filter. Seemed to be fine. Yesterday the "pollen" was back on the bottom of the pool. Again, ran the vaccuum except this time the yellow/green "pollen" was simply circulating from the vaccuum to the filter and right back into the pool via the return jets. I am now looking at a completly green pool. The pool is approx 14.5k Gals. The pool store has been telling me "more conditioner" now for 2 weeks. My numbers are as follows: FC 1.5; pH 8.0; TA 100; CYA 45 and phosphates 500. Salinity 3700. So here is my question. Can add Bleach without damaging the SWG (Pentair, Intellichlor) and IF so how much. Any other ideas how I can get rid of the green water and debris on the bottom after the filter has been off for a few hours. Thanks. Doug
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,094
Houston, Texas
Hi Doug, welcome to TFP! I am going to ask one of the mods to create a thread for you so the advice for you doesn't get mixed up with the advice for Jill.

We recommend shocking with liquid chlorine ( 6% bleach or 10-12% from the pool store) even if you have a SWG for 2 reasons. First it saves wear and tear on the cell and second the SWG cannot produce chlorine in the quantities needed fast enough to effectively shock the pool.

First you need to lower your pH to the 7.2-7.5 range. 41 ounces of Muriatic Acid will drop the pH to around 7.2.
Next you need to raise the FC to shock level which is 16 ppm for your pool as per the pool calculator. You need to keep the pool at shock level until the pool passes the overnight FC loss test (you lose less than 1 ppm FC from dusk to dawn, you have .5 or less of CC, and the water is clear).

After you complete the shock process you will need to raise your CYA to 70-80 ppm if you plan to continue using your SWG. SWG create chlorine slowly and require a higher CYA level to prevent the FC from burning off too quickly. The higher CYA level allows your SWG to keep up with demand. Add enough stabilizer to raise the CYA between 70-80 and adjust the SWG so the FC never drops below 2.

I am assuming you have a plaster finish on the pool? Do you know what your Calcium (CH) level is?

You need to keep your pump running 24/7 during the shock process, and clean the filter as needed. Shut down the SWG during the shock process.

Do you have a test kit? You will need to be able to test high levels of FC during the shock process so you can calculate how much chlorine to add during the day. We recommend the TF100 or the Taylor K2006. Both kits contain the FAS-DPD test you will need to test high levels or chlorine.

If you have any questions please ask. Good luck with your pool!
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,179
SWSuburban Chicago, IL
Hi and Welcome

Can you put your pool's equipment and specs into your signature? Go to User Control Panel, then Profile, then Edit Signature.
Zea gave you great advice - you need to shock the pool.

Shocking Your Pool

rather than pollen it does appear that this is algae (one clue is the FC level which is too low). Leave the filter running 24/7 while shocking.

More info on the filter?
 

dmalin

Member
Sep 7, 2010
5
Central Florida
Thanks guys. I added the acid last night to bring the pH down. My reading this afternoon is 7.6. Not as low as I think it needs to be but. . . .I used the pool calculator and added 546 Oz of 6% Bleech to bring my TC up from what looked to be very close to 0. How long before I need to test again? What is the TC/FC goal (16?) and how long do I need to keep it that high? Thanks. Doug
 

dmalin

Member
Sep 7, 2010
5
Central Florida
One more question - for now anyway. I have a 7 panel solar system. Should I turn on the solar system to make sure the "shock" treatment gets to any growth in those pipes/panels during this process? Thanks Again!
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
23,062
SouthWest Alabama
It's not a bad idea to run the shock level water through every piece of equipment you have for a few hours during the last phases of the shock treatment. You should run it for a few hours after the FC has returned to normal too just to ensure that you don't leave high FC water in it for an extended length of time.
 

dmalin

Member
Sep 7, 2010
5
Central Florida
Thanks Dave. That is what I thought made sense. I have the panels on now and will let them stay open for a few hours and then turn them off. And, as you suggest, I will open them again later in the "shock" process. Doug
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,094
Houston, Texas
dmalin said:
Thanks guys. I added the acid last night to bring the pH down. My reading this afternoon is 7.6. Not as low as I think it needs to be but. . . .I used the pool calculator and added 546 Oz of 6% Bleech to bring my TC up from what looked to be very close to 0. How long before I need to test again? What is the TC/FC goal (16?) and how long do I need to keep it that high? Thanks. Doug
You want to keep the FC as close to shock level as you can until the shock process is finished. Test the water and add bleach every couple of hours. Do your last dose just before you go to bed. Keep the pump running 24/7 and clean the filter when there is an 8-10 pt pressure rise. The shock process is complete when you have passed the overnight test.
 

dmalin

Member
Sep 7, 2010
5
Central Florida
Okay Guys, I have been at this "shock" process for about 20 hours now. Lost approx 10 on the FC overnight and added bleech per the pool calculator this morning. Here is the question - my pH is back up to 8.2. Can I / should I add acid to bring it down while dumping all this bleech into the pool. Last night when I went to bed my numbers were: Hard 500; TAC 20; FAC 20; pH 8; TA 120 and CYA 30-50. This morning my numbers were: Hard 250; TAC 5; FAC 5; pH 8.2; TA 120 and CYA 30-50. I added 14 liters of bleech per the bleech calculator to shock it back up to near 20 based on my CYA. Should I now add acid to bring the pH down or just wait and let the process work. The pool is looking better as in less green and a bit more clear. Thanks. Doug
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,094
Houston, Texas
The pH rise from the high FC levels will drop when the FC levels drop. You don't need to adjust for it during the shock process. If you FC drops below 10 ppm and the pH is still around 8 then you can use MA to bring the pH down.
 

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