You can plant it deeper. But not yet. If it's only an inch tall just leave it in peace. Make sure it has lots of light and take it off the water heater.

@floral - I have already removed it from the water heater for a few days. Its the next to the window in the kitchen. I might move it outside tomorrow, to start hardening it off. I forgot to move it today. Tomorrow is suppose to be fully cloudy and 75.

Thanks. When I put it in the soil, i will bury it deeper.

For me cucumbers do not do well if started indoors. They don't usually take to being transplanted well and just sit there not doing anything for awhile after transplant. I always direct seed now and the seeds sprout in less than a week and grow much better than transplants.