What is this?

[Matthew Wallen]

I live in Southern California.
My chem has stayed within normal limits.

However, my pool timer clips slid together and my pump didn't run much for a few days and white mold developed on pool surface.

I'm wondering what this brown stuff is.
Is it dead Algae?

I been trying to waste water vac it out which is challenging since I have cartridge filter and no super easy way to fast waste water vac. I just been using a shop vac.

 

[Texas Splash]

It's not dead algae. If anything it looks like live algae. I don't see Poolmath test results linked to your profile, can you post a full set of water results?

 

[Pool_Medic]

When brushed Algae goes poof into a cloud, sand or dirt just scoots along.

 

[Matthew Wallen]

When brushed Algae goes poof into a cloud, sand or dirt just scoots along.

It goes poof into a cloud

 

[Matthew Wallen]

It's not dead algae. If anything it looks like live algae. I don't see Poolmath test results linked to your profile, can you post a full set of water results?

On Sunday
Ph 7.0
fc 10
combined Chlorine 0
Calcium 400
Ta 60
Cya 90
Borate 60

On Saturday same except fc was 5.

 

[JamesW]

Possibly mustard algae.

I would do a full SLAM.

 

[Texas Splash]

Matthew, your pH is in good shape to start a SLAM Process. Your challenge is the elevated CYA of 90. According to the FC/CYA Levels, that would require an FC SLAM level of 35. So you have the option of increasing the FC to 35 now and maintaining it until you pass all 3 SLAM criteria, or you can exchange some water in an effort to lower the CYA (for example around 50) which would require a lower FC level for the SLAM. Totally up to you.

 

[Matthew Wallen]

Matthew, your pH is in good shape to start a SLAM Process. Your challenge is the elevated CYA of 90. According to the FC/CYA Levels, that would require an FC SLAM level of 35. So you have the option of increasing the FC to 35 now and maintaining it until you pass all 3 SLAM criteria, or you can exchange some water in an effort to lower the CYA (for example around 50) which would require a lower FC level for the SLAM. Totally up to you.

Thanks, I'll start the slam as is. It isn't mid-summer or anything so pool isn't getting used at the moment anyway.

 

[Matthew Wallen]

Thanks, I'll start the slam as is. It isn't mid-summer or anything so pool isn't getting used at the moment anyway.

My wife did the last borate check on the pool. Some how, she got that it is 90, not 60 like I originally thought. Could that cause some foaming on surface of the pool? I have no idea how the borate level is 90

 

[mknauss]

Could that cause some foaming on surface of the pool?

Not likely.
Borates come from adding LOTS of Borax or Boric Acid. No other source.

 

[Matthew Wallen]

Not likely.
Borates come from adding LOTS of Borax or Boric Acid. No other source.

I added boric acid last spring. Last night my Chlorine was 38. This morning my chlorine is 35. I've kept my Chlorine at 35 since Saturday. I've scrubbed with nylon brush 4 times a day. I've used pool blaster vacuum etc. Last night I 100% cleaned the cartridge filter. This morning there was very, very little "poof" algae and there was very little surface white stuff here and there up against edges of pool. I'm thinking if by tomorrow it isn't 100% gone I'm just going to drain and refill.

 

[Matthew Wallen]

So, after days of brushing, doing waste water vacuum etc. and nearly giving up and doing a full pool drain. This morning my overnight Free Chlorine test showed no loss, the water is clear, and no CC. So, I took the filter apart to clean it and there is the sand substance on top of the filter. What is this?

It's not dead algae. If anything it looks like live algae. I don't see Poolmath test results linked to your profile, can you post a full set of water results?

 

[Texas Splash]

It looks like sand. Is it gritty like sand?

 

[Matthew Wallen]

It looks like sand. Is it gritty like sand?

Yea, sorta... but my wife and I haven't been to a beach and I've cleaned the filter 3 times since we last went. We are the only ones that live here.

 

[wireform]

You may have a very windy conditions last couple of days and possibly sandy dust blowing and got into pool. Not far fetched.

 

[Texas Splash]

Matthew, earlier in your thread there was a concern for algae or possibly even Mustard Algae. We know there's a different between sand and algae where sand will have that typical gritty feel, while algae will be thinner, slimy, and/or powdery once it dries. It looks like yesterday was the first day you seemed to pass all 3 SLAM criteria, then you opened the filter one more time to clean it and noticed all that stuff. If it wasn't clearly gritty like sand, it may have been dead algae. I'm assuming you cleaned the filter yesterday, so I'd just keep an eye on things for a few days. Watch your FC consumption and perhaps do another OCLT in a couple days to see if everything is stead. Perhaps that substance was dead/residual algae material that just needed to be rinsed out from the SLAM.

 

[zea3]

Any chance pollen is collecting in the pool? Anything dusty/dirty looking collecting on horizontal surfaces outside?

 

[JamesW]

Maybe aggregate from the plaster.

 

[Matthew Wallen]

Any chance pollen is collecting in the pool? Anything dusty/dirty looking collecting on horizontal surfaces outside?

I live in Bakersfield, CA... the entire town is dusty.