Plastic Filtering Sunlight?

Greetings,
Longtime indoor grower just working my first outdoor grow this year. 1 week into flowering and big fungus gnat issue because lots of rain here in VT overwatering.
Green Crack crossed with mystery strain, bag seed I got in some bud at a special price from Colorado dispensary before we moved. 22 gallon totes organic soil getting about 6-8 hours of direct sun.
To wipe out dem gnats I put up a huge (clearish) plastic sheet that came with some studio foam I had delivered.
Anyhow, the plastic is doing a fine job blocking out the rain but I’m just curious if it will effect the potency by filtering light with it getting minimal daily sun. Any thoughts? Should InI roll up the plastic when there’s no rain?

I too use plastic sheeting as protection from eyes and weather. I've done a bit of internet searching with not much success. The best i could find was the super thin stuff (I use .3 mil) can block up to 10%. If the plastic has a uv blocking coating it seems like that would have an effect on resin production, as the resin is produced in part to protect from uv light.