Whitish tomato and pepper leaves

O.k., I did some research today on this site and others on the internet because my tomato seedlings and only pepper seedling had their leaves turn whitish overnight. They have been outside now for about a week and coming in at night because of the lower temps in Mass. From what I can gather it could be several things- sun/wind burn, over watering or lack of nutrients. Shouldn't be lack of nutrients as we are using fresh MM in cups and box. I'm just worried that it could be some kind of fungus because of the possible over watering and it will get into the soil in my sfg because I put in 2 of the tomato's and 1 pepper on Sunday. May 6, was the last average frost for my area and we have a green house covering the box besides and we close the flaps at night. I think some of my options are- wait a few days to see if anything changes, and or try adding some type of fertilizer such as fish emulsion. They have never had a nice semi dark green to them. I considered just pulling the 3 plants out of the box just in case and purchasing some to take their place. My wife wants to save the lot as she has hope for them but I'm not so sure I do. What do you guys think???

I had the same thing happen to mine. They were all perfectly healthy and looked great, but when I began the process of hardening off, the leaves began to turn whitish. I saw no spots for evidence of pests, just discoloration. I put mine in the ground, and after a few days they perked up. Of the 12, all recovered but two Roma plants. I'm completely new, so my advice isn't worth much, but I trimmed the damaged leaves and planted them into the ground. I think that was on the 1st.

We've had rain for the last three days on and off, and that has really seemed to get them going...but I do worry that it's going to continue to rain for three more days!! Anyway, I'm anxious to see your responses and see if I did the right thing.

The tomatoes have sun scald on the leaves (sunburn) don't worry about it. Not sure about the peppers.

Thank goodmess, Boz, I left my new toms out in the sun for too long today as I did not get home in time to move them into the shade. I'm happy they will recover.

Most of my lot still is not looking too good but I might keep one tom and the whitish pepper in my box. Probably trim off the bad leaves and plant deeper as I didn't plant them quite deep enough the first time. Can you do that with peppers or is it just tomato's that will send out new roots along the stem when you plant them deeper?