Sandbed sounds like it working fine, but still need to age.
I am willing to bet that it is your new lighting that has caused it.
For your consideration:
I would, limit the amount of time that your lights are on. I had a similar experience when I went from 80watts NO lighting on my 55 to 380 watts VHO. What I did was to turn the two 50/50 bulbs around so that the bright side was facing up for a month and lessend the photo period. It took a while (can't remember how long now) until the algea had finally subsided, it was terrable hair algea that I had to pull by hand and syphon as well as scrub the rocks clean.
I would also run carbon to try to absorb some of the organic matter that seems to be in your water so fill that canister up.
Chemi Pure is also a very high grade carbon with resins that would be good to use.
Make sure that you have enough water movment on the top of the water colum for oxygen exchange. If you can not point one of your powerheads up toward the surface then see if you can add a saddle filter like the penguin with the bio wheel.
Try to find the polyfilter by Bio Marine and place it in your canister filter as well, this more than anything will show you just how bad your water is, this filter really pulls the DOC's out! as well as phosphate. I have notice one drawback to extended use of polyfilter and that is that my leather corals tend to close up. These can cost 10 or 11 bucks at an LFS but can be found online much cheaper for the 4x8 size, and can be cut to any shape you need to fit, they would work well in your canister or a saddle filter.
If you can't find the polyfilter anywhere let me know and I will give you my email and let you know where to find them.
I believe that you are suffering from poor filtration as well as the affects of the new lights. Having added the cansiter filter, fill it with carbon and see if that helps over the next week or two.
Adding a protien skimmer would be a very good idea
Good luck
Thomas
