the rock is at 1'-4". bridges is a -III at this level. it is about 2 miles long.
bring a mtn bike and do a few laps. it is a long drive from larime for this level so spend the day. put in below pine view falls on the first lap and maybe run it on the second lap if you like what you see. nice and slow.
I've kayaked Filter Plant at roughly 150 cfs and don't recommend any lower. There were at least a half dozen spots where it was very shallow and I got hung up temporarily in my hardshell. Fortunately, it's a great level for my kids and they don't get hung up much unless they're using an IK. I was up there this past Saturday afternoon when it was at 215 cfs. I got hung up twice in shallows but otherwise it was a great level for kid and newbies alike, aside from rock dodging.
If Filter is too low and you're looking for an easy run you can put in at the Diamond Rock day use area (a mile+ upriver from Poudre Park community) and float down to the take-out right above the Hewitt Gulch Bridge. I took my kids up there on Labor Day when Filter was too low and we did 1 mile laps. Rock level was at 1.1. Only real rapid is Doc's Drop in the middle of the run and can be scouted from the rest stop. It has a big recovery pool below the drop.