I think what you have with organic ferts in molecules that are of too large of size to be absorbed. this is why you need bacteria to break the stuff down to a level plants can take up. this process takes a while. typically, once these ferts are in the soil, there really is not flushing them out, but then you shouldn't have to as you depend on the break down rate from bacteria to provide ferts over time. I've advocated the use of organic ferts, but the problem is they take longer. Ideally, a grower allows soil to sit in a container, moist and warm, for several weeks before using. the good thing about chemical ferts is they can be used right away; the bad thing is they can easily be over done.
yeah, I was confused about you dosages. In reviewing this thread, I stand by what I said earlier because you are apparently using liquid ferts which might already be broken down for easy, quick use. because the leaves are dark green with dying tips, I still think there is too much fert here. I'm not always right, I could really be missing something here, but right now over fert is what this looks like. I just don't see how salt buildup can be seen as the cause of leaf death when much of the leaf still looks so green. I suspect that this is just too much nitrogen. but it will be interesting to see how this plays out. personally, I think I would give some more water and see what happens.