Dirt or Algae? New pool owner

[Randy698]

This probably gets asked a lot and I’m sorry but here goes. I have a new fiberglass pool and the surrounding area is still dirt. No concrete walkway yet either. I’ve been getting what appears to be dirt (see pictures) collect in the same spots. When I touch it sometimes it’s gritty and feels like dirt. Other times if brushed it puffs into a cloud. Just got my SWG fired up last night and until then have been adding liquid chlorine but not been at consistent levels. I brush it often and use a machine floor cleaner which gets the pool looking nice but then the "dirt" comes back. Looking at the pictures can anyone tell me if it looks like dirt or algae? Once I get my chlorine levels stabilized I'm going to do a OCLT. I will also try cleaning my cartridge filters.

 

[mknauss]

You are on the right track to do an OCLT.

 

[Wobblerlorri]

No need to wait to do your Overnight Chlorine Loss Test. Go out to the pool in the early evening, after the sun is off it, and test it. Bring the FC up to your normal level according to the FC/CYA Levels, then let it circulate for 30 min. Test again to get your baseline.

Then leave it alone until morning, before the sun gets on it. Test again. You pass OCLT if you lose 1 or less in FC, and have 0.5 or less in CC.

 

[Randy698]

Here are my results from my OCLT
Evening
FC 4.2
CC 0
Ph 8
Alkalinity 130
CYA 35
CH 250

Morning
FC 4.0
CC 0

Looks like I’m good on it not being algae, correct?
Hoping once concrete surround goes in and grass comes back I’ll have less dirt in the pool.

 

[Wobblerlorri]

Did you scrape off some and smear it on a white piece of paper? Just for grins and giggles.