I might try a microfiber cloth slightly dampened with water.

Plexiglass is a trademark for a particular type of plastic but the word has become genericized, much like Kleenex has for facial tissue. There are two clear plastics commonly available, acrylic and polycarbonate, and they MAY have different cleaning requirements. If you are so inclined you might want to determine which plastic you used and then check with the manufacturer for their specific cleaning recommendations.

I would be careful using anything other than just a cloth moistened with water. As stated above, there are different ones, and I'm thinking that alcohol might sort of eat into, or cause actual smearing of the plastic. Might you have a scrap of the plexiglass left over that you could test some cleaners out on, in case plain old water doesn't do it?

hi-
Thank you both for your input. I think I will stick with
water. Knew coming here would help :)

I had a big plexi greenhouse,occasionally I would dust it,the rag scratched the plexi,you have to be real careful.