I use orchid mix to make an already chunky mix chunkier - as well as faster draining ....the rocks, twigs and bark take up the space that would others hold water ...we dont want to hold any water ....on and gone
curled new leaves, yellowing leaves are all under-watering - and not enough direct sunlight - through a window is not direct sun ...
watering once every two weeks in the summer months are "starving" them ....
droopy leaves is another sign of under-watering
your plants caudex should be "drinking-up" water and storing nutrients - making the caudex grow outwards ...instead of "drinking it up" - the plants are "using it" to stay alive ...that's why you see the shrinking, yellowing, droopy
put plants outside and saturate them .... use a fertilzer
leave them outside to soak up the suns rays ...and if it stays in the 90's ...water again in 3-4 days
