Slightly blue but clear water

[Endro32]

The water sparkles in the sunlight, you can see the fine details on the bottom, and it looks clear. But it's ever so slightly blue-tinted such that the walls and stairs look bluer towards the bottom. I don't think it's algae, because my overnight free chlorine loss is consistently less than 0.5ppm (and I haven't heard of blue algae), and I don't think it's just an illusion because when I scoop some out into a white 5-gallon bucket, it looks blue in there, too. My only two theories are that there's some dead algae in the water that the sand filter just isn't pulling out, or there's some kind of mineral in the water (we fill our pool with well water) that's giving it that coloration. It's also very possible algaecides and/or clarifiers have been added in the past by our facilities guys before I took over. The water's quite pleasant to swim in and otherwise very good, I'm just not happy with the blue tint. Any thoughts on what might be causing it and how to fix it?

This in our 60,000 gallon MI pool, btw.

 

[YippeeSkippy]

I believe clarifiers do sometimes come with a bit of dye a to see them on the shelf its pretty obvious how deep blue they are.

 

[Endro32]

Well there is a half-empty bottle of polysheen blue sitting on a shelf in the pump room, which definitely is blue. Assuming it is just dye from the clarifier, does it harm the water at all? Is it worth it or even possible to get rid of it?

 

[YippeeSkippy]

No, no way to get rid of it short of draining and refilling. Sadly that stuff can gum up filters if used more than maybe once?

Maddie

 

[tim5055]

If yuo think the sand filter needs a "littel help" you could also add DE to your sand filter to allow it to filter the fines better: Pool School - Add DE to a Sand Filter

I actually use a cellulose fiber DE replacement and find it works well: https://smile.amazon.com/Pro-Guard-23793BPG-Cellulose-Replaces/dp/B00D3J3G4W/