Fiberglass stain or algae?

[NewFGOwner]

Hello, just came home from pool store where I mentioned I have what looks like faint stains on my dark blue fiberglass pool. They were quick to say to treat it as algea and use an algea treatment. It just doesn’t look like the black or green algea photos I’ve seen on line. Any advice on how to assess the stain or whether it’s algea? I hate to over treat it or treat it incorrectly. Any suggestion on brand of test kits if applicable? I’m going to try to get better pictures when it’s sunny tomorrow.

Thanks!

 

[mknauss]

Read through this -- Stains in Your Pool - Trouble Free Pool

 

[mknauss]

For test kits --

Order a TF-100

The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want.

I also have the Speedstir. It makes testing much easier.