Alge or debris?

[scader]

I'm commonly seeing settlement at the bottom of my pool, mostly on the shallow end and side of pool that has the returns. For a while, I thought it was just organic matter that was blown into the pool and settled.

So my question is: does this look like a) settled organic matter, b) alge, c) sand or such from equipment failure

My robot vaccum picks it up, but then it's back in a day or two. I recently had a 40-person youth party and after liquid shocking the pool it's been cloudy, but this issue persisted before even after completing a SLAM. The only thing low is CH at 190. It's been a struggle to get water clear since my late-open in June.

 

[Rancho Cost-a-Lotta]

Can you post a set of test results?

 

[Rancho Cost-a-Lotta]

You should do an Overnight Chlorine Loss Test. It's not looking too good...

 

[scader]

FC 5
CC 0.5
PH 7.6
CH 190
CYA 50
TA 55

 

[scader]

I've been loosely doing an OCLT almost every day, but getting out there a little late (9am). I'll SLAM tonight along with an OCLT.

Another question: due to late opening with pool mostly drained, the deep end of the pool has a faint alge stain ring. I presumed that's just a stain as it won't scrub off. Is that wrong to assume?

 

[Rancho Cost-a-Lotta]

Nothing obvious sticks out in your numbers. Your TA result (55 ppm) is invalid for both formulas (10mL and 25mL samples). Time for an OCLT.

 

[Rancho Cost-a-Lotta]

I've been loosely doing an OCLT almost every day, but getting out there a little late (9am). I'll SLAM tonight along with an OCLT.

Another question: due to late opening with pool mostly drained, the deep end of the pool has a faint alge stain ring. I presumed that's just a stain as it won't scrub off. Is that wrong to assume?

SLAM time.

Don't know about the stain...doesn't show in the photos. A more detailed description and photos may help. Take a look here for identification guidance:

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

 

[scader]

I redid my TA and it turned pink at 9 drops, so 90ppm at 25ml. Going to SLAM and OCLT tonight.

It's a bit difficult to see the green stain while cloudy, but for reference, here was the water line while I was doing pool repairs in the shallow end...

...and today:

 

[Rancho Cost-a-Lotta]

I see the stains now. If they're organic stains, a slam should help or remove them. Let's see if @JamesW can take a look...

 

[JamesW]

Is the pool painted?

 

[scader]

Is the pool painted?

Yes, epoxy paint. The deep end is paint from before we bought the house a few years ago and had the alge water during the shallow end repairs.

 

[scader]

So I incidently bumped the FC to 31ppm (SLAM calculator said goal was 22), but the pool does look more clear. In the morning it had dropped to 26ppm, so need to maintain the SLAM.

 

[wireform]

Any slam level above the FC/CYA ratio is waste and the FC drop in your case can simply be the higher chlorine not protected by the given CYA you have.
You have a SWCG pool and need a CYA of 70 but that should wait till the slam is truly complete. You showed a FC of 5 so for a chlorine pool it was low and for the SWCG it is not recommended. Aim for the 70 CYA and keep FC on the hot side of target closer to 10 to never skirt danger with algae again.

 

[scader]

Raising FC to 30 wasn't intentional, but I thought during OCLT the FC would only drop due to alge or other contaminants?

I plan to get to 70 CYA once I complete the SLAM, but I'm also confused that 10ppm is a safe level of chlorine? For years using a SWG I kept it at 2-3ppm/60-plus CYA, so this is going to be a mental shift.

Did some reading online...why does SWG chlorine break down faster requiring a higher CYA? I thought higher CYA was simply to help keep FC from swings.

 

[scader]

@JamesW don't want to loose that part of the discussion...any advice for removing the alge "stain"?

 

[JamesW]

Yes, epoxy paint

Paint stinks and I hate paint.

I would never use paint.

I would remove the paint and plaster the pool.

The problems are likely to be related to the paint.

Otherwise, I can't really tell what the issue because the pictures are not very good.

Can you post better pictures?

 

[scader]

I missed this update, sorry. It stinks bad. I didn't know you could have an unpainted, plaster pool. Lots to learn, still.

While bad, I don't have the funds to replaster at this time. Is there such thing as an alge stain or is it always just alge to remove?

I should have taken new pictures before the aftermath of my daughter's birthday party turned it cloudy. *sigh* I'll post better pictures after I slam it.