Organic stains resurfacing each day???

[JoeMX82]

I have an in-ground two year old pool with a pebbletec surface. Test results below. With fall starting here in Houston I get the occasionaly organic leaf stain that when I raise my FC goes away overnight. However, the past few days I have noticed something strange. I have a raised hot tub will a spillover into the spill where a step is directly under the spillover. This step area had a large, irregular, pattern of light brown staining on it. Not in the typical leaf shape and not in an area where leafs had been sitting. I used a puck and scrubbed it over the stain, waited a couple of minutes and brushed it away. Thought nothing of it until the next morning it was back... Repeated same process but now I have done this four times, removed all leaves from pool each day (never ending battle as surrounded by trees) and starting to wonder what in the world is going on? Any ideas?

CL - 4.0
FC 4.0
TA 85
PH 7.7
CYA 80
CH 300

 

[YippeeSkippy]

You don't mention how you sanitize your pool, but since your CYA is so high I'm going to assume its a SWG?

If it *is* a SWG pool, your FC is at the bottom of what is desirable. If you're sitting at 4ppm, how likely is it that it sometimes goes below that?
Based on this I would suggest you raising your FC level up to 6-7ppm which allows for daily loss yet you shouldn't see it go under 4ppm. [FC/CYA][/FC/CYA]

 

[JoeMX82]

Thanks for the reply - I do not use a SWG, I now use bleach only as I realize my CYA is too high. I will raise my FC but why would these stains reappear in an area with no leaves to begin with? I do not have staining issues anywhere else in the pool and I get a lot of leaves each day.

 

[duraleigh]

There are thousands of species of algae and I believe one type has found your old leaf resting places irresistible. You have algae, not stains.

I would first read "The ABC's of Pool Water Chemistry" up in Pool School. Then I think you need to SLAM the pool. Look up the SLAM article in Pool School to see how that is done.

 

[pooldv]

Agreed. Your FC is too low for your CYA. FC should never drop below minimum to keep the pool sanitized and algae free. [FC/CYA][/FC/CYA]. To kill the algae follow this process, SLAM Process