I agree that it looks a bit thin, but it is hard to tell from the pic. How many ounces of skimmate does 24 hours produce? My Remora (non nano version, fairly loud) only pulled maybe 1-1.5 ounces of gritty "green tea" per day from my lightly fed 24g
FOWLR.
I just ventured to the Red Sea site to look at your model. Is it a venturi, and airstone or both? If it has an airstone, make sure to change it regularly for best performance.
If you want to upgrade, but don't want to deploy a
sump (and you can spare the dough), then the Tunze Nano 9002
skimmer would be my first choice. Compact, discrete, relatively quiet and decent skimming for a nano
skimmer. If you want to run carbon, the Tunze Reefpack 200 may be an interesting combo.