Cfl first grow...

It's my first cfl grow , but I have many years of bonsai experience ... I started from seed and the plants are 3" tall in one week... I'm using one cfl300 watt 6500 k ... The plants are about 3" away from the bulb ... I'm using my own bonsai mix which is 1/3-colorado lava rock-1/3-high fired clay and 1/3 pine bark... The soil has a balanced hp of 6.5-6.0.....I don't know when to feed aggressively .. I'm using ghp and already used the seedling mix once yesterday . All other waterings are clean hp water.... If u use ghp on your grow ... Please reply... If you don't , information is always good, but may not apply to my certain situation ... Thanks