They look fairly good right now. But if you haven't flushed them lately, now is a great time to do so. I believe in proactive flushing, that is, flushing to prevent problems, instead of fixing them.
My best advice for effective flushing is to use warm water. I have this spot by my fridge and it puts off heat, and when I set my RO jug by it overnight, the water is warm enough to bath in, perfect for flushing. People think flushing means rapid release of an insane amount of water. Use the warm water, wait about a half hour, and do it again. The first time breaks up the salts and mineral build ups, the second time gets 'em out.
IF you already do it this way, great, but anytime I give flush advice, I always like to cover my bases and make sure people don't sit there with a hose and force feed 5 gallons of cold water on an already sick plant.