hey there Tamber, what's happening is the 4 hours of sun is actually not enough, and that's why the seedlings are "stretching" , growing too tall, show signs of stress like a red stem. Overall, it will be alright, but right now and in the mean time, you do need to manage the stretch. that means you'll have to monitor and provide support to the stretched out plants either by adding a bit more soil at the base of the plant or even using stakes etc trying to replicate LST. Hope this helps ! 🚀