I've done the same recently (i'm a first time hydro too). Moved three plants from soil to hydro. One bhut in DWC and a hab and a fatalli in a modified dutch bucket kinda set-up.
I adjusted pH and got the ppm in the 400-600 range and my plants looked similar to yours for about a week. Saw some burn/bubbling on the old larger leaves and a bit of yellowing too. You could try top watering a bit until the roots grow into the reservoir below or as GoTrox says fill the res higher.
After a week or so I saw the older leaves that burnt the worst are dropping off, but the new growth is coming back quicker than I have ever seen in soil and its nice and green, with only a very slight bubbling. Coincidentally, I noticed that the plants started to look healthier when the roots got about 1 inch below the bucket. So, I would not panic. They might not look pretty for a while, but they will probably come good.
More experienced hydro people like GoTrox might see rebound after a couple of days, but if you are like me and a total newbie, it took a week or so of playing about with the strength of the nutes, pH etc to get them close to correcting the lockouts, burn issues etc. Are you running all the plants from the same reservoir like me?? If so, the challenge I've found is that my plants are slightly different sizes (all classed as seedlings I guess) and are different types of plant, so their nute requirements are different. Therefore, I've accepted I'm probably always going to have some bubbled leaves or minor burn issues for a while.
Good luck though dude.
