Has anyone ever used Seachem Purigen? Says it's a synthetic polymer. Thumbs up or thumbs down in a oscar aquarium?

No, I've never used it before. I'm always slightly dubious about anything that says it can control nitrate. Have you actually use it yourself yet? If you have, maybe you could do some kind of a review at some stage.

I just put it in my filter today. Will see what happens.