In a mixing bowl, combine the cucumber slices, onions, and green peppers.
In a saucepan over medium heat, combine the salt, celery seed, vinegar and sugar. Bring the mixture to a boil. Allow the mixture to cool for 10 to 15 minutes.
Combine the mixture in the mixing bowl with the mixture in the saucepan. Pack into sterile jars and refrigerate for 24 hours.
