We used a black light on our carpet last night and found black spots. When we turned on the lights we didn't see the spots. What stains turn black under black light?
i would bet its the dye...........piss would would be yellow,semen whitish,
Protein stains, such as urine, blood, semen, will glow with a whitish tint. I've checked a thousand carpets with a black light,in total darkness, mainly to assess the extent of urine contamination so a decision can be made to either treat the stains or tear the carpet and pad out. I have never come across black stains as you describe them. In any case, even after extensive hot water extraction cleaning, the glow will remain. In your case, whatever caused the spots you see is probably long gone from the carpet, just the residual effect remains, which is permanent.
