I'm trying to use 555 timer to open a valve 12V-1amp,I'm controlling my humidity by a drip on a small towel & small fan I' using the wet towel as a veryable resister to control the timer I get relay chatter between 1&0 Ben

 

Post a drawing of what you have so we can see if there are any errors/problems.
Also, I suspect this will get moved to the proper place, as this is for feedback.

 

No circuit, but a guess based on your complaint: Put some hysteresis in your comparator circuit.