Going into 3rd day of SLAM to kill algae...

[Potful592]

I'm heading into the 3rd day of SLAM today to kill a few stubborn algae spots on steps. I'm brushing pool and scrubbing algae spots with wire brush as well several times daily. Scrubbed the spots on Saturday with a trichlor tablet as well. I'm following all instructions on this site. and had zero FC loss overnight so hopefully/maybe I'm making progress.

Pool is in shade most of day - we moved here last year so this is my first spring season with this pool and I'm thinking this algae battle will be a chronic problem.

QUESTION: Considering that I may have to keep FC on the high side to keep the algae away (7.8), is this FC amount "comfortable" to swim in? Skin/eyes?

 

[mknauss]

Can you post a full set of test results?

pH is the primary reason for skin/eyes issues with water. Followed by CC. FC is fine to swim in up to shock level for your CYA.

 

[Richard320]

Green patches on the steps should just brush off. They may come back, but it sounds like yours never left. And that makes me wonder if the algae isn't embedded in Calcium Scale. Does the offending patch feel rough?

Or is this black algae --- really dark (almost black) dots?

You can swim with FC up to shock level with minimal discomfort. The CYA buffers it (think buffered aspirin) so the actual active ions are less than in tap water.

 

[Potful592]

Can you post a full set of test results?

pH is the primary reason for skin/eyes issues with water. Followed by CC. FC is fine to swim in up to shock level for your CYA.

FC 20
CC .5
PH 7.8
TA 80
CH 210
CYA 50

 

[Potful592]

Green patches on the steps should just brush off. They may come back, but it sounds like yours never left. And that makes me wonder if the algae isn't embedded in Calcium Scale. Does the offending patch feel rough?

Or is this black algae --- really dark (almost black) dots?

You can swim with FC up to shock level with minimal discomfort. The CYA buffers it (think buffered aspirin) so the actual active ions are less than in tap water.

Thanks for the response. I'm pretty sure this is black algae - (very dark dots that start as dark brown and turn black) they spread very quickly into many spots before I started SLAM process. 99% of them are gone now but still have a stubborn "stripe" of algae on steps. I haven't felt the spots so not sure of the texture.

 

[Richard320]

Thanks for the response. I'm pretty sure this is black algae - (very dark dots that start as dark brown and turn black) they spread very quickly into many spots before I started SLAM process. 99% of them are gone now but still have a stubborn "stripe" of algae on steps. I haven't felt the spots so not sure of the texture.

Yeah, sounds like black algae. You can confirm it by scraping a dot (if any are left to scrape) with your fingernail, then smearing it on a piece of white paper. It'll look real dark green when spread out, black when concentrated.

I assume you've read this, but just in case.... Black Algae - Trouble Free Pool