Yellowing/dying Leaves on Tomato Seedlings

saiwha

This is my first time starting tomatoes from seed and everything had been going smoothly until a few days ago. It started off with a slight yellowing of the cotyledons and has then spread to the leaves with some of them wilting/dying off. A single leaf had a couple of yellow spots on it but after looking today I can no longer find it to get a picture.

From my googling I thought that this might have been because I had got a bit carried away with watering them, I let them dry out a bit over the last 2/3 days but they seem to be getting worse.

Can anyone identify what the problem is and how I can fix it?

/dying

hogweed

Could they have had water on the leaves and then scorched by the sun? The other possibility is that they are too wet. It will take more than 2/3 days for them to recover if it is that. Only water them when they are dry and water directly into the compost. 

saiwha

There is a chance that they could have got water on the leaves, I usually only water them late evening/before I go to bed.

With regards to the watering, some are looking like they could do with a bit of a drink. Should I wait a bit longer or give them a bit of water? Also I am watering from the top and hear that that can cause issues, should I invest in a gravel tray to water from the bottom?

Lyn

I wouldn’t worry about that, you can snip them off, When you repot you need to bury up to those anyway, so I’m sure they’ll be fine. 
Im a no nonsense gardener,  don’t worry too much about things like that🙂

hogweed

It looks as though your compost is shrinking away from the sides of the pot. They need water!