It is probably best to wait till the second set of true leaves start to grow before you transplant to seperate pots. Sounds like like too much water as well. Unless it is very, very hot you shouldn't be watering them every day. Best to let them dry out a bit between waterings.

Thanks for the help. How deep should I repot them? I repotted 9 plants up to the seed leaves and they have all withered, so I thought that I planted them to deep. Then I planted 3 to about where the soil was in the seed flat and they died too. I'll wait until the second set of leaves emerge but I'm worried that a disease may be attacking them.

Miracle Grow Garden Soil or Miracle Grow Potting Soil??? MG Garden Soil stipulates right on the bag that it is NOT intended for use in any containers. Not only is the fertilizer content too high - especially for seedlings, but it drains poorly unless used as an additive to the garden as it was intended. Your seedlings are overstressed from the fertilizer and likely developing root rot due to poor drainage and overwatering.

Miracle Grow Potting Soil is also quite high in nutrients and is inteneded for established plants, not new seedlings. There are several threads here on GW about how to properly use these products that a search will pull up.

I suggest you buy a bag of Jiffy Mix or some other seedling mix (something with little or no added fertilizers) - tomatoes don't need them anyway - and transplant your survivors to cells of it. When translplanting make sure the new cells of soil are well wet first (not soaking) and then set the seedlings in as deep as possible. The tomato stem will develop roots all along its length.

Lastly, for future reference, there is a good (not great) How to Grow from Seed FAQ here that is linked at the top of the forum page. Good luck. :)

Many people repot with only the first set of leaves, so that shouldn't kill them. And as long as you aren't burying their leaves, the planting depth is fine. The water sounds like it could be too much, but in a peat pot, it's pretty hard to kill them with overwatering. I've used them in the past and had the opposite problem...they would dry out too fast. As for diseases, I would think the ones in the flat would get it too.

I'm wondering about the soil you used. Some MG mixes have a LOT of fertilizer in them...or maybe some got mixed in somehow. Also, are you getting the soil nice and wet before re-potting? I usually mix it in a bucket with water until it's saturated. Otherwise, it doesn't become absorbant. The water just sits on top and only the surface of it gets wet.

There probably dampening off due to excessive cloudy weather and overwatering.

Are stems rotting in half in one place just above the soil line?

Yes timmy1 they are rotting just above the soil line, the roots seem to be fine though.

Sorry about the mix up, I am using miracle gro potting mix, which has 0.27% nitrogen, 0.07% potassium, and 0.14% potash.

MG potting mix is fine, it's a favorite on the WS Forum and I am sowing all my tom seeds in it this year. It sounds like you have damping off. At this point you should sow more seeds in larger containers so you don't have to transplant. Styrafoam coffee cups are fine for this. Use a pencil and poke one hole in the bottom for drainage and they're ready to use.

A number of things can lead to the dampening off. I already mentioned the long duration of cloudy weather and overwatering. There are some fungicides that will help.

Never water in cloudy weather as the plant tissue will remain moist for a long period of time. Keep the temperature above the dewpoint and the dewpoint below the temperature. Use steril soil, containers and tools to help stop the spread of pathogens.

This is the MG soil that includes fetilizer. It's way to hot for young seedlings. I accidently used it for repotting seedlings that were older than yours. They turned yellow and started dying. I pulled them out of it, put them in my usual mix and they recovered. Switch to a mix with no ferts and you'll be fine.

I would not recommend Miracle Grow potting mix for starting seeds. I planted a whole bunch of various seeds in it and after two weeks not a single one came up. So I recycled the potting mix and used it to repot some tomato seedlings I started in some other brand. So what do I see two weeks later, lots of tomato seedlings sprouting next to my transplanted seedlings. I figure as I kept watering the potting mix I eventually leached the fertilizer out of the potting mix, and I think that fertilizer was inhibiting the seeds from sprouting.

This sure sounds like DAMPING OFF, a fungal disease of seedlings. Too much moisture, not hot enough, plants too close together, often happens when transplanting tomatoes.
When I first saw it I thought the stems had been pinched at the soil line by insects. They were also a little brown right there. Lots of info at Univ. of Minnesota site.

www.extension.umn.edu/distribution/horticulture/DG1167.html