I also have TS3000 and recently started my first grow with it. While I think you're seedlings were over watered, I've had to raise my light to 3 feet above my seedlings/plants and keep the light dimmer to 50% to avoid burning them and stopping leaves from "canoeing".
I'm not sure when to lower the light or dial up the power, but I know it was burning all my plants at 24 inches and 50%.
For seedlings or small plants 3 feet and 50 percent is the ticket on the TS3000.
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