I had several varieties of tomatoes that were all growing really well, until I went on holiday, and decided to bring some seaweed and seashells back with me.

I applied them to the garden thinking they would make great fertilizer, but several days later, the lower leaves started going speckly, and crispy.

I'm not 100% sure it was the seaweed tea/crushed seashells, but there's no other explanation (other than virus or disease).

Can anyone identify the issue, and please tell me if it's terminal, or can the plants recover?

Many thanks.