The hydra 32 is a great light, I have not used it on a tank with those dimensions but I would recommend it because in my opinion the worst case scenario is you could have some light spill past the edges of your tank and that’s easily fixed with a diffuser. Some reefers here sell custom diffusers for that model at the R2R market place.
As for bacteria I would suggest bio spira but I don’t think it’s necessary if your bringing your live rock over from your current tank.
A good thing to keep in mind with tank transfer upgrades is the coral and parameter swings. Most dry rock I’ve dealt with, raised phosphates then a few weeks later the rock sucked in phosphates and coral like their phosphates stable. What I do is, add my dry rock and add at least one rock from my old display to the upgrade. I also add bio media from the old sump to the new sump. This is where the bacteria comes from and after a couple months I start bringing in the coral. I’ll add fish to the upgrade about a week or two after adding the rocks (test and double check for ammonia/nitrite). At the end I will have added all the live rock from the old tank and any bio media that doesn’t look exhausted.
If your not using bio media an alternative can be to add some filter floss to your current tank and give it a few weeks for the bacteria to colonize. I recommend you only add some of your old sand to the new tank for the bacteria benefit. I’m one of those reefers that believe sand harbors more then just harmless detritus and so most of it should be removed and rinsed thoroughly before reusing.
Good luck reefer and congratulations on the upgrade!
