1. Your Container "might be" too small.
2. They appear underfed; lacking Nutrients!
3. What is Your Soil; "PH"?
4. What is Your "Lighting Source"? MH Bulb? What Wattage?
5. Rather than "water" when dry, consider "feeding" 2-3 X's daily, and we're not talking anywhere near a pint!
6. ANY "Source" of CO2?