hmm...are you sure it;s due to lack of light?maybe you already knew this but i would just like to repeat it again that emersed HC already used to "unlimited" supply of co2 and when you flood the tank that time, they got co2 only from what you supply them.from my experience doing DSM, first 2 weeks after flooding it, spam the tank with co2 alot. then reduce slowly day by day until the rate you want so the HC can adapt themselves to the changes and preventing drastic environment changes.

22W for 1.5ft for me personally is not enuf anyway. after flooding the tank, the lights will be reduced when reaching the HC. but for me, since you've grown it emersed with that same light, it wont be as critical as the co2 supplies.

can fit hundreds.... but better start off with 30-40 shrimps.... jz set ur budget rm50 for RCS alone...