Its not completely crucial but plants would appreciate not having the chlorine.
Chlorine is not so much the problem anymore... Chloramine is (a compound of Chlorine and Ammonia--more and more commonly used nowadays in place of Chlorine). It is more stable than Chlorine and harder to remove. Simply boiling or leaving your water out overnight won't do the trick--but there are methods.
Before possibly wasting any time/effort on a bagel result, I would check to see what is added to your local water. No use trying to remove Chlorine if it is Chloramine in your water.....
Contact your local water department. They have to tell you what they put in your water, and in my state they are required to publish a yearly report of the results of any testing.Is there an on-line resource for this, or do I need to purchase a test-kit?
If you have ever been in a heavily used swimming pool on a hot day and noticed your eyes stinging, you have been subjected to chloramines. Swimmers have been pissing in the pool and the chlorine has reacted with the urine, killing bacteria but forming chloramines. ... So if your eyes sting, get out!
Camden tablets contain Sodium Metabisulfite. Dissolve them in water and you get Hydrogen Sulfide gas. Wineries use them to sterilize fruit juice, but then have to let it stand and breathe awhile to get rid of the gas before adding the yeast.Campden tablets are a quick and easy way to remove chlorine and chloramine from tap water, I don't know what their effect on plants and soil would be.
An excess of peroxide does no harm