I use aspen bedding, and i find that it is easy to spot a pee spot even if there is not a urate there as drynaspen is light yellow and a pee stain Will be a light Brown colour. Its very easy to spot and Will stand out wHen you see it.
And A's some one has suggested you Will definately smell the pee spot! Enjoy and good luck pee spotting.
1.0 Pastel Graziani ( Sir Henry) " Henners " 2010
0.1 Stinger Bee " Barbara " 2010