I have been using a similar (larger housing) 10w blacklight to light up my 18' spider web and it works well.How do you like those black lights? I've been thinking of adding a few to our spider web area of the yard to highlight the web. First ones I tried were 50W and ran way too hot to leave outdoors on the grass where we have flammable fallen leaves. Wondering if these would be bright enough.
It seem a guy think 3-6w is plenty enough to light up a spider web. SpiderWebMan.NET