Black Algae Treatment Help

[cr0ntab]

Hey All,

I've been fighting with black algae in my pool for some time, scrubbing - slamming, scrubbing - slamming, scrubbing - slamming and it keeps coming back.

It's starting to get worse as it's showing up on the floor of the pool now (no idea how I'm going to do a good job scrubbing that)

I'm almost certain it's because I can't get the crevices of this rock feature 100%, everywhere else I hit with the metal brush and things work well.

(I've come to hate this stupid water feature, it's going to be flat plaster or flat concrete if/when we redo it)

Does anyone have any tips to get into this section of rock feature?

I have half the mind to jump into the pool with a pressure washer and hit it hard and close.

 

[mknauss]

Have you confirmed it is Black Algae? Read Black Algae - Trouble Free Pool

Have you been maintaining elevated FC levels (not just SLAM, SLAM process is not for Black Algae)?

 

[cr0ntab]

Have you confirmed it is Black Algae? Read Black Algae - Trouble Free Pool

Have you been maintaining elevated FC levels (not just SLAM, SLAM process is not for Black Algae)?

Long response here, but full context.

It's definitely black algae, I used the paper test to confirm.

Most of this started because my SWG died this summer and I figured it out late after I came back from a vacation.

I was manually dosing liquid chlorine for a lot of the summer, but I wasn't 100% diligent on it. While using the liquid I kept CYA ~50 (the middle of the range from the CYA chart)

I finally got the SWG replaced and it's been running for the last 2 week-ish averaging about 3-4ppm (so not on the high side of the FC band)

I'm in the process of pulling the CYA up to 80 (there is a bag of stabilizer slowly dispersing into the pool), it measured about 55 this morning (halfway between 50 and 60)

I'll certainly clean up my FC/CYA act in the coming weeks and really stay on top of this.

I've followed the TFP method for some time, so I know where I need to be on the FC/CYA side of the house, I've just been lazy (and i'm now paying the price)

 

[mknauss]

I would NOT raise the CYA at this time.

You need to maintain about 15-20% of CYA for your FC level. That will make your pH test invalid.

 

[cr0ntab]

I would NOT raise the CYA at this time.

You need to maintain about 15-20% of CYA for your FC level. That will make your pH test invalid.

Alright, I can remove the bag of CYA, the intention was just to get back to the bare minimum on the SWG chart here:

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

Since you mentioned pH, that's always been a real pain in my pool.

If floats up constantly due to (what I believe) is the spa overflow water feature. That's constantly aerating the pool water and raising my pH.

I go through quite a bit of muriatic acid to keep things in check.

 

[mknauss]

You have an Intellicenter. You can use SpillWay to program in the 20 or 30 minutes needed each day to chlorinate the spa, then just use Pool Mode the rest of the time.

CYA is best at the recommended levels when your pool is normally operating. Yours is not.

 

[cr0ntab]

You have an Intellicenter. You can use SpillWay to program in the 20 or 30 minutes needed each day to chlorinate the spa, then just use Pool Mode the rest of the time.

I do have the Intellicenter, but I didn't spring for the IntelliValves when I installed it (they were a bit out of budget when we first got it).

Either way, a good call out and even though the valves are expensive, it should save me on costs in acid over time. I'll look into purchasing those.

CYA is best at the recommended levels when your pool is normally operating. Yours is not.

Understood, I just went out to pull the CYA bag.

 

[mknauss]

Do you not have actuators on your spa return and suction valves?

 

[cr0ntab]

Do you not have actuators on your spa return and suction valves?

We don't right now, it's just the manual 3 way valves.

As such, I leave them normally configured to return from the pool and supply to the pool.

However, the supply to the pool has a small bypass to supply water to the spa.

 

[mknauss]

OK -- you do not have to have Intellivalves. Just normal actuators.

 

[cr0ntab]

OK -- you do not have to have Intellivalves. Just normal actuators.

Good to know, I'll get to looking for some valve actuators to help with the waterfall/acid consumption.

 

[cr0ntab]

Circling back on my original question.

Anyone got any good tips or tools to get into the crevices of this rock feature to take the head off of the black algae?

I have this small algae brush, but it's still not small enough to get into the cracks.

Maybe an even smaller wire brush will do the trick?

A bit of reading says that pressure washing isn't exactly recommended because it could mess up the plaster.

 

[Katodude]

I use a bamboo bbq skewer. I just pick at the spots. I would put some LC into a pump sprayer and then hit the spots that you have picked at with a high dose.