Well i know that they need more nitrogen in this stage, i think that npk solution is not the proper one for veg stage you should have something with more N than P. I had 3.5-1-5.5(BioVega) and it worked perfect in veg stage, i never lost a single leaf. It was my first grow so im not some kind of profesional but from all the help and reading i always read that you need more N than P for veg. I think you should give them only water for the next couple waterings and see what happends, if you can buy them botled PH balanced water.