Neglected pool maintenance during winter, now trying to clear algae

Piggulet

Member
Feb 27, 2021
5
Metro-Atlanta, GA
Hi!

While I am new to this forum, I am not new to pool ownership and have successfully combatted algae blooms in the past with SLAMming the pool. This go round, I am baffled.

Before raising the chlorine levels, I checked my numbers:

pH 8+
FC 0
CYA 25
TA 40

I added muriatic acid to lower the pH and got it a little too low at around 7. I added 13 lbs of Baking Soda to raise my TA to 40(which I know is still low). I added 6 gallons of 10% liquid chlorine, Brushed the pool in its entirety. Several hours later, I tested the chlorine levels and got a reading of 30+. The next morning, there was no drop in the chlorine level, which was shocking. I continued to add chlorine thinking it was just a misread on my part.

Now, my pH indicates purple, which I know can be caused by high levels of chlorine. I read in another thread that lower water temps can make this process slower. Do I just need to wait and not keep adding chlorine? Please help!!!

Thanks in advance,
Piggulet
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
23,657
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
What is your water temperature?

What made you think you had algae? Did you do a Overnight Chlorine Loss Test?

What are your FC and CC now?

Your CYA is 30. If the dot disappears between 30 and 20 we round up and call it 30. You cannot measure CYA 25.

Your SLAM FC is 12.
 

Piggulet

Member
Feb 27, 2021
5
Metro-Atlanta, GA
The pool is green which is why I think I have algae. Yes, I measured the chlorine at night and then in the morning, there was no loss. The water temp is 55 degrees. My chlorine level is well above 12. It is not clearing up.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
23,657
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Sounds like metals in the water. Have a pool store test your water for metals - iron and copper.

Cloudy with a tint of green = algae

a pretty overall green tint but clear = metal

MOST of the time that is.
 

Piggulet

Member
Feb 27, 2021
5
Metro-Atlanta, GA
Yeah. It is not clear. There was definite algae on the bottom of the pool. Brushed, now it's cloudy green. Appreciate your willingness to help. Can't understand why it isn't clearing up as it has in the past. I know the liquid chlorine is not too old. Wondering if there is some other water chemistry interfering?

After getting the purple color on my pH test, I have stopped adding anything to the pool, but let the pump run continuously.IMG_20210301_130259024.jpg
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Once you lowered the pH to about 7.0, best to forget about it during the SLAM Process. An elevated FC will make the pH read higher until the FC falls below 10. But during the SLAM Process, FC testing and consistency is a priority, trying to maintain the FC of 12 (in your case) until all 3 SLAM criteria have passed. Many owners have that one season that simply doesn't react like the previous. :scratch: But I would get the FC to 12 and keep it there as best as you can all day long. Do all the other tasks on that SLAM page as well. Even if you do have metals, which is questionable at this point, you must complete the SLAM first anyways.
 

Casey

TFP Expert
LifeTime Supporter
Apr 16, 2007
11,843
SW PA
Pool Size
17000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
And don't over dose the pool on chlorine. It's a waste of product and can destroy your liner.
 

JJ_Tex

Gold Supporter
Bronze Supporter
Jul 17, 2019
2,293
Prosper, TX (DFW)
Pool Size
13000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Keep at it. Sand filters usually take the longest to clear up the dead algae. How long did your previous SLAMS take? Just by looking at the pictures, I would expect yours to take 5+ days.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Some items that may help with progress:
- If your CYA is actually 30 (rounded up from slightly less), then an FC of 12 is ideal and should be maintained
- Ignore further pH results until after the SLAM Process
- When was the last time you did a sand deep clean? It may be time
- When you initially brushed and made everything cloudy, any chance there is more junk settled at the bottom?
- Is your filter pressure gauge working? Remember to backwash when the pressure increases by about 25% from the clean starting pressure.
- How old are your test reagents? Any chance they were compromised by extreme heat or cold?
- Did you add any other chemicals other than baking soda, acid, and liquid chlorine recently? Anything new in preparation for winter?
- Are you testing the FC at least 3-4 times per day to maintain the FC of 12?

Hopefully some of that will help.
 

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