I don't think you're totally effed but they are a bit stressed and will most likely be delayed if you can resolve the issue....

You say that you only nute every two weeks??? Water every 3-4days??? Maybe your probs are due to deficiencies....and I bring this up because you are using a soil less mix.... Think about using a medium that has soil in it for your next go, like FF Ocean Forest or FF Happy Frog....something that cannot be used as a hydroponic medium....

What is your soil pH??? I don't recommend using tap water but that is just me....could also be part of the prob....

No runoff??? So does the excess water sit at the bottom until the plants drink up the moisture??? Not understanding this portion of your setup.... Is it a recirculating water system??? You doing hydro or soil???

Also, if you think there is a build up of salts, you can always flush the medium/roots....

CGI::::::