There's no need to start over. Dig your hand down into the soil and see how wet/dry it is. Check before and after you water. You have to feel the soil in the root zone. How deep is the soil before the gravel layer? How wet is the soil at the gravel level? Why don't you water enough for water to come out the bottom? Water thoroughly then allow the soil to dry slightly before watering again.
Add some white fluorescent tubes - at least 5000k. 6400k is best. Plants use all the colors of the light spectrum. By giving your plants only red/blue light, you are slowly starving them. It is true that plants use mostly red/blue light but, consider the other colors as micronutrients. But, plants were built to sort the needed colors themselves, they do it all the time.