people say alot of stupid shit with respect to hydroponics.
you dont have to remove chlorine what so ever from tap water.
if you want to, and it makes you feel better to do so, thats entirely a different matter.
i maintained a pool for my entire childhood. in the summers we ran it up to 7-10ppm free chlorine and 100 ish CYA, and the splash out?( the water literally splashed out of the pool)
the plants LOVE the splash out... the grass immediately around the pool deck is noticeably taller and greener, though owing to a lack of proper watering on my part, not due to any inherit health benefits to pool water.
mind you 7-10 ppm free chlorine is an order of magnitude higher than that levels you would ever see in a residential water distribution system.
i worked for many years at an engineering firm designing, among other things, small private water systems.
i wont get into the chloramine deal because it does not matter. but if you live in a semi decent sized city, you will have pretty large water plants, and your municipality likely uses chlorine dioxide disinfection owing to low costs.
if you have very hard water(the hills of dover are chaulk right?) , you will likely run into scaling issues with calcium precipitating out of your nutrient solutions as calcium carbonate.
have you mixed a test batch of nutrient solution, to the desired concentration?