I have said this before, but it works for me so I will mention it again. I don't put lights on my top shelf, but I use the top shelf for germination because the heat from the second shelf rises and heats the soil. To better conserve this heat that is being generated anyway, I use mylar camping blankets that I buy for about $3 in the camping department at WM and throw them over the top and almost enclose 'the germination chamber'. On occasion, I have let one hang down the back of the light shelf where the plants are growing. It is bright and shiney and reflects a lot of light toward the plants. Since I am already paying for the electricity, I might as well use all of the heat and light that is there. I have never owned a heat mat.

Hi tworivers - would it be possible to post a picture of them? It would help a lot. Are these true leaves or just the cotyledons - the seed leaves - that are damaged? It is possible to scorch very young seedling leaves if they are too close to the light - happens to most of us now and then - but the plants will usually recover. And it's especially true if you mist the plants or if it is too hot in your growing area. Is it enclosed so that the heat is trapped? Got a thermometer near the plants? A small fan to lightly move the air will help. Only other thing I can suggest without see it is to lightly touch it and see if it will rub or brush off on your finger - that would tell us that it is some sort of mold or fungus. Keep us posted on what you find or if you can post a picture. Good luck. Dave

I'm not finding photos of necrotic blight, but other blights show darker spots with a circular pattern not seen on my leaves. Also my fruit is unaffected. Septoria Leaf Spot sounds and looks similar to what mine have. Either way, the treatment is removal of affected leaves and a copper spray. I will do both as well as a preventative spray on my other tomatoes. Thanks, Omni.

Could be, although I am checking weekly-ish with a digital moisture meter how the soil is towards the bottom. I water thoroughly when it reads zero or close to it. I read that they like high humidity. Being in California, not so much. So maybe it would require some more regular misting and taking it a bit away from the window?