Chlorine will evaporate out in about a day if you fill a tank and let it sit. You can use an aquarium air pump and air stone, or a recirculating water pump to speed the evaporation process. However, a lot of places use chloramine, not chlorine, and that takes more like a month to evaporate out of water. You can call your water company and ask which one they use.

Had blackout cellular blinds in a previous house. They blocked light in our east facing bedroom well. Some light seeped through the edge as expected. They block a lot more light than the non blackout. The two issues I had with them are they're functional but not decorative and it's almost all or nothing with the light. The blinds are open and let in light or closed and block most of it. In my office it wasn't easy to block the glare but keep some light.

We've had the bamboo roman shades up for almost five years. A home was just built on the lot next to us so I felt that my teenage soon needed something more private. I cut a piece of drapery liner to fit the back of the shade and attached it at the top by hand sewing to the brown thread on the back of the blind that holds the slats together. I untied the cord from the rings, pulled the cord out (of just the rings) cut a small slit to fit the liner over the rings and then threaded the cord back through. I then attached the liner at the bottom of the blind by again hand sewing it to the thread that holds the slats. When raising or lowering the blinds you cannot tell they weren't made with the liner in place, meaning the liner and roman shade fold together. Like nanabella, I feel I lost the look of the woven blinds when the liner was added but his room is darker and more private now.

I am not a professional but will give you some advice based on my experiences. I made a pinch pleated drape for my large sliding glass door several years ago. We have a wood overhang outside which blocks some of the afternoon sun. I did not line the drape but I did use buckram in the header. The fabric was medium weight home decor cotton...not super thick. After sewing the header, there was a lot of stiffness & thickness in the header for the pleats. If I was to have also included blackout lining in that header, it would have been too heavy & thick for me to work with. It may be a good idea to make a separate blackout lining in your case. I would make the lining about an inch less (than the finished drape) in width as well as length. I have sewn a small window panel that included blackout lining sewn in to it. I did not do pinch pleats for this panel. I used rings & clips instead. The blackout lining was inserted into the header before sewing. I used a double fold of the fabric at the header but did not fold the blackout. The blackout goes all the way up into the top of the header. Same idea for the side hems...the fabric is double folded but the blackout is not. The blackout did not need to be sewn at the bottom...it's not sewn in to the hem. Hope this helps a little. Back side of small drape with blackout (rings & clips) Bottom hem and sides