5FC, 0CC, Yellow Algae?

[Dabrodas]

Hi all!

Long story short.. pump died and I ended up installing my own and firing my pool service. During the two weeks the pump died, pool slowly turned green.

Ran the pump for 48hours and SWG on super chlorinate. I thought I was good to go after cleaning the cartridge filter and pool was crystal clear.

Ended up adding stabilizer and been working on getting my SWG locked in to the right levels based on chlorine loss.

This was the past three weeks or so. Fast forward to today and while all my levels look great, I’m seeing Yellow on the walls that when brush, turn into a cloud. Pool is still crystal clear.

Is it possible I need to SLAM to get any remaining algae out? I thought 0CCs meant I was ok. I guess I need to do the OCLT?

I am worried now since I dialed in my CYA to 70... lol

All my logs should be in pool math

 

[Donldson]

Hindsight is 20/20, but you should have performed the SLAM Process immediately after restoring circulation. Running the SWG for a couple days might have cleared the water, but that doesn't mean it got everything which seems to be the case. The zero CC doesn't mean anything, CC is indicative of certain substances in the water, not algae. No need to bother with an OCLT, it's a test for organics but since you have visible algae that's not necessary.

Start the SLAM Process and run that to completion. I have my doubts that what you're seeing is true mustard algae (and hopefully I'm right), but the first step regardless is to SLAM the pool. In the future (of course, hopefully it doesn't happen again) a pump failure is not a guaranteed green pool. You can manually dose chlorine and then brush the pool to circulate it. Even without filtration you could potentially go for days doing this without the water even turning cloudy.

 

[Dabrodas]

Hindsight is 20/20, but you should have performed the SLAM Process immediately after restoring circulation. Running the SWG for a couple days might have cleared the water, but that doesn't mean it got everything which seems to be the case. The zero CC doesn't mean anything, CC is indicative of certain substances in the water, not algae. No need to bother with an OCLT, it's a test for organics but since you have visible algae that's not necessary.

Start the SLAM Process and run that to completion. I have my doubts that what you're seeing is true mustard algae (and hopefully I'm right), but the first step regardless is to SLAM the pool. In the future (of course, hopefully it doesn't happen again) a pump failure is not a guaranteed green pool. You can manually dose chlorine and then brush the pool to circulate it. Even without filtration you could potentially go for days doing this without the water even turning cloudy.

Thanks. Yeah, hindsight is 20/20. I didn’t fully understand the TFP method until after my pump was installed and I ran the SWG. I was planning on having my pool service handle the green.. but after reading TFP decided to fire them.

I’d have to do a drain to get my CYA levels down big time.

what else could the yellow be? Pollen? It’s weird, it’s really only on the side walls and not the bottom of the pool.

 

[Donldson]

Oh it's algae, I just think it could be run of the mill green algae that looks a bit yellow against the pool surface. Just given everything your pool has been through I like to start with the assumption that it's green algae until there's more to back up it being something more exotic.

You could perform the SLAM Process at 70 CYA, but keeping the FC at 28 does mean burning through the testing reagents faster. Which is cheaper and/or easier to do is up to you.

 

[Dabrodas]

Thanks for this - I ran my FC up to 23 over the weekend, brushed, brushed, brushed and looks like my CYA is closer to 60. Did two OCLT and they both were within 1FC. Pool is clear, brushing wasn't yielding any more yellow. I was surprised to measure 15 FC today (from 21 yesterday), but it has been hot and sunny here in FL, but losing 6FC in 24 hours w/ SWG going seemed extreme.. but those are high FC levels.

My filter was also green, from the previous pump going down, so cleaned that all out and it also solved my "pump bubble" issue and dropped my standard pressure from 15PSI to 10PSI. Due for a new filter as well. Also found out my pool light is leaking, and had algae all inside the light fixture... will be putting it back until I feel up the courage and $$ to buy a new fixture.

Now I am dealing with hundreds of tiny flying ants in the pool!

But aside from that, I think we are all set and will be playing with my SWG % and pump timer to hold the 5-7FC PPM. Will check FC again tomorrow afternoon!