Some "dust" like stuff comes off when I brush, is that algae? And is it normal, or should there be zero if the pool is well balanced?

[Mayday]

I have a SWG pool that is clear, and has been so a long time. I've never had an algae breakout, green water, and so on. Pool is in Jacksonville, covered with a screen so only pine needles disintegrate and fall through.

Still, when I brush (admittedly occasionally) dust like stuff lifts off some of the surfaces in the water, maybe more often the steps, but also walls and the floor. It's like brushing a dusty floor where you can see the dust coming up and making a bit of a cloud, but in water. It settles and I push it towards the drains. I am assuming this is algae, is that right? Or is it other organics?

Is it normal for that to happen, or does a well balanced pool produce zero of that when brushing? In other words, is it an indicator to shock?

Water seems balanced otherwise- Ph is 7.4-7.6, FC is around 4-5, Stabilizer is around 60, TA around 70-80, CH around 250. Both Chlorine and stabilizer were indeed low at one point before starting summer season, but I SLAMed, upped Chlorine, then upped CYA.

 

[mknauss]

Welcome to the forum!
Do an Overnight Chlorine Loss Test
Likely dirt. Do you run a pool cleaner that goes up the walls?
I suggest you read through Pool Care Basics - Trouble Free Pool and even look at a few of our videos TFP-TV - Trouble Free Pool

 

[Dave31410]

I live in Savannah, close to the coast, and it is frequently windy here. Also the soils are mostly fine sand. Then most of the lawn companies use zero turn mowers that have a very high blade speed and kick up a lot of dust, along with the blowers. All of these factors combined mean that I get fine dust in the pool frequently.

 

[Mayday]

Welcome to the forum!
Do an Overnight Chlorine Loss Test
Likely dirt. Do you run a pool cleaner that goes up the walls?
I suggest you read through Pool Care Basics - Trouble Free Pool and even look at a few of our videos TFP-TV - Trouble Free Pool

I didn't even really think that the thing that looks like dirt could actually be dirt. I thought "it's a pool of water, how can it be dust and dirt? "

I will check overnight Chlorine level loss again, but I don't think it's much.

 

[wireform]

As @mknauss pointed out a OCLT is in order here to rule out algae. Being a salt water pool the minimum CYA should be 70 and the target would be 5-10 but better to be in the higher/hot end of target for wiggle room so not to skirt danger with algae. Even at the 60 you have 4-5 you mentioned is bare minimum which leads to problems as you may have already.

 

[Mayday]

As @mknauss pointed out a OCLT is in order here to rule out algae. Being a salt water pool the minimum CYA should be 70 and the target would be 5-10 but better to be in the higher/hot end of target for wiggle room so not to skirt danger with algae. Even at the 60 you have 4-5 you mentioned is bare minimum which leads to problems as you may have already.
View attachment 603806

I thought the chlorine rule was 7.5% of the CYA, which for 60 would be 4.2. I didn't think of this as bare minimum and I need to be higher, I thought this was the target. Am I wrong in that?
And the CYA can be between 60-80; I don't think anything I read here says 70 is the minimum; it's more the mid point target.

 

[Newdude]

And the CYA can be between 60-80; I don't think anything I read here says 70 is the minimum; it's more the mid point target.

You have much harsher UV in sunny FL than I do in NY. 60 works better for me, 80 is likely better for you.

Your daily loss will be similarly higher without a cage and you may need to dose over target to land back in it after said daily loss. The closer you run to min, the more you have to pay attention that you don't dance the line too close.