your soil looks like flora base or something comparable...so thats good...
2 x 24" 52 watt @ 6700k also sounds good...are they both white bulbs or do you have one blue (actinic) bulb? if you have a blue bulb remove it ASAP as they are notorious for accelerating algae blooms and they don't offer any value to plants.
how are you adding your co2? Is it pressurized or home made? by the looks of what you started with and where you are now it seems like it's possibly not enough co2 but it's hard to tell from a distance.