Hard Film on Waterline of Pool

[robmartin113]

Moved from here.
I seem to have a similar issue going on only my issue is above the water line. Magic eraser will remove it but it takes scrubbing, and scrubbing, and scrubbing, one layer at a time.

I have no idea what it is being as its above the water line. It was there when I removed the cover last night and I can't seem to find any answers online. First time it has happened, but no change to my normal winterizing process in the fall.

 

[IceShadow]

I seem to have a similar issue going on only my issue is above the water line. Magic eraser will remove it but it takes scrubbing, and scrubbing, and scrubbing, one layer at a time.

I have no idea what it is being as its above the water line. It was there when I removed the cover last night and I can't seem to find any answers online. First time it has happened, but no change to my normal winterizing process in the fall.

Do you have a good test kit like a Taylor K-2006c or TFT-100? If so what are your numbers? Maybe it's scaling but we'd need to know your chem levels, and pool store testing is impossible to trust.

 

[robmartin113]

I dont have either of those kits. Just one of the “deluxe” dropper kits. Initial Readings were as follows:

pH - 7.6
FC - 0
Combined Chlorine - 0
CYA - 0
Alkalinity - 200
Salt - in range per SWG. Don’t have actual reading.

New here so thought my pool info was in my bio when I downloaded the pool math app.



Pool is around 16,000 gallons. SWG. Vinyl liner.
Closing process last year was same as I’ve been doing for years with both my parents pool, and then this pool when I bought the house 5 years ago. I know the pool is very old but never had this issue before.

photo attached. Note: pool was in process of being filled when taken. The staining or whatever it is was only on the portion of the liner from the winterized lower water level up to where you see it in the photo.

water did accumulate on the pool cover but I pumped off when it thawed out in spring time.

 

[robmartin113]

Updating. Manager at local pool store said she has never seen anything like that but thinks it is some combination of mold, algae and colorant from some construction debris that blew onto the mesh cover over winter. We had our house redone so that was the source of some of that pieces of asphalt roof.

She had me SUPER chlorinate the pool. The entire thing sounded like a freshly poured seltzer with how much it was fizzing. Water this morning looking much better and the portions of the black stains in question that are under the water surface at this point seem to come off much easier than the dry above water portion with some scrubbing.

I'm still just baffled and want a definite answer. Not speculation from a pool store owner.

 

[mknauss]

I'm still just baffled and want a definite answer. Not speculation from a pool store owner.

Get a proper test kit. Only accurate water chemistry data will guide you to a safe and sanitary pool.

 

[robmartin113]

That's on order!