sight glass green

[Miniman]

I have noticed in last week my sight glass on my intex sand filter is greenish and looking bad. I have backwashed 2x and rinsed but that still is green. Pool is perfectly clear
any have any answers about that? Is there ever an occasion to open the filter and look that way?
Please

 

[jblizzle]

The sight glass on my filter is removable so I can clean it. It only sees water when backwashing, so the stale water sitting in it will allow algae to grow.

Not sure if the Intex is similar, if so, just remove it and clean it out.