Algae Just Won’t Go Away

[Txpoolgal17]

I seem to have two trouble spots in my pool for algae. No matter how high I SLAM, they never fully go away. I’m on day 2 of a SLAM and the algae has turned from black to green but still remains. They’ve probably been in my pool for 2 years now at some capacity.

Midland, TX so lots of sun and hot
My pH is 7.2
CYA - 35 to 40
FC - 19 ppm this morning. I will test again soon. I’m using liquid chlorine to raise.

The rest of the pool looks gorgeous and sparkling. But this spot and one other never goes away. Can algae get stuck in plaster? This is an older 2005 pool.

 

[kul]

The slam method can take time and needs to be followed exactly. How often have you been adding chlorine and checking chlorine? Are you brushing that area repeatedly?What’s your overnight loss? What are your current levels and what kit are you using?

Pool Care Basics
SLAM Process
Overnight Chlorine Loss Test

 

[Txpoolgal17]

I’m using the Taylor pool kit. This is the first time opening our pool this season (we keep it closed with a cover in the winter), but all last summer I had the same problem. I just lived with it . I didn’t SLAM but once last year.

I have the dolphin pool vacuum that’s constantly running over the area but hand brushing? Not often. I started hand brushing hard yesterday a few times a day. 2 days ago I added 4 gallons of liquid chlorine 10%. I was pretty much at 0 chlorine before that. I added another 2 gallons yesterday. This morning my FC was 19 ppm (Free and combined chlorine test). I’ll check again this evening and then again in the morning to see my loss. I was going to jump in and pick it at with a tougher tool tonight.

I haven’t checked alkalinity and hardness in awhile but I have very hard water where I live. My Taylor water gram balance calculator always said I was in range If that’s helpful. Do either of these impact ability to get rid of algae? Thanks!