So I took a quick look at the Finnex Ray 2. For a 24" it's about 50 mmol per square inch of PAR if you sit it on the tank. For a 36" it's about 90 mmol per square inch of PAR sitting on the tank. I've already factored in the depth of each tank (20H and 20L) into the PAR ratings. I have no clue what is considered low/med/high when it comes to PAR. I found this thread
that's just as confusing. Along with this thread
. The members in the first thread are saying 35-50 is medium, but the second thread says otherwise. If you end up with a 20L that would be awesome (I love those dimensions much better)!