10/2 or 12/2 wiring for 220v 20amp tanning bed?

Dtstellwagen read your question correctly. The manufacture calls for a 20 amp circuit and 20 amps it is. Therefore #12 wire. As to voltage drop, I don't see it in 75' (or in my opinion 100') but that's me. Now then, you didn't leave 25' of wire coiled up in the attic or such did you? No offense but that sounds just entirely too lazy! Now then, do tell me you connected it to a 2 pole breaker and not 2 single pole breakers. Hmmm?