Chlorine mostly,i used to be able to use my tap water for years,up until about 8 months ago,now i can't use it for clones or seed starting or my plants,soil grower by the way
Is this of interest
How long does it take for Chlorine to fully evaporate from tap water?
Depending on its levels of content, the evaporation time for chlorine from tap water can be estimated:
2 ppm of Chlorine will take up to 4 and a half days or around 110 hours to evaporate from 10 gallons of standing water. Ultraviolet light, water circulation, and aeration will speed up the evaporation process dramatically. Chlorine will last between 6 and 8 minutes in 10 gallons of boiling tap water. Boiling is the fastest method to remove Chlorine from water.
I use tap water. The wter into my house if filtered with two in-line 2.5" x 10" filters. I added a second stage to my filtration when I started growing, because I am using living soil. Particulate filter, then a charcoal filter for the chlorine.
There is a pic of the filtration in my gallery, but the new software makes it too hard to go get it for this post. That part of this new software really sucks.
Here it is: https://www.icmag.com/filedata/fetch?photoid=17696071
You need a carbon filter for chlorine. If th city water dept has changed to chloromine, you need a better carbon filter. If I ever run a tap off my laundry room water to have a remote hose to fill the reservoir, I will add one of these filters to that line:
https://www.amazon.com/gp/product/B0051VC7CW
I use a Hydrologic Tallboy filter for the garden. Where I’m at, it’s the chloromine, which doesn’t dissipate like chlorine. I think it uses a KDF filter and a sediment filter. There are cheaper hose attached filters, can’t remember the name, growmore maybe?
make sure you know what you want to filter out before you buy a filter.