I had the same prob;em with my plants except they turned a dark green the leaves became shiny before they started turning yellow wish I would of know this before hand
well how do i flush em? i took them out of the original water, water the roots out and put it in freash water.. is that what you mean?
you could do some research on flushing. should find something for sure. but what you did probably just was the right thing to do, keep an eye out. your plant will be stunned in growth for now, it will take her some days to recover and continue growing. keep in mind that the curled leaves wont "uncurl" again, they will stay what they are. just watch that the curling doesnt extends.
also looks like your over watering them. check your ph. check for bugs to. bugs can cause problems. looks like it could be nute burn. how much nutes are you giving them. try using half the does and cutting back.