How to Tighten a Roller Shade
Roller shades use a tube with a spring inside to operate. When you lower the shade, the spring coils up inside the tube. This provides tension to raise the shade when you want to open the window. The spring uses a pawl and ratchet between the spring and tube end, to allow the spring to move in only one direction. Sometimes the pawl will miss the stopping ratchet, and the spring will lose some tension. You need to partially reroll the shade to tighten it. This process may take several attempts, but this gives the spring the proper tension.
Pull the shade down halfway. This will coil the spring inside the roller shade shaft.
Remove the roller shade from the brackets. Lift up on the roller shade on the open end bracket side, and pull the shade out of the enclosed bracket.
Roll the shade tube by hand to evenly roll the shade fully around the tube.
Insert the shade into the enclosed bracket, and set the other end inside the open bracket. Operate the shade as normal. If necessary, continue making tension adjustments until the shade will fully open when you operate the shade.