I have used pellets ever since they were available on the market. The trick is to use a smaller percentage of the recommended for the size of your system and see how well it controls the phosphates and nitrates. The second thing is the skimmer is needed to remove the byproducts of the bacteria...
You just take apart the top and remove the existing fixture and install the new ones. not much electrical has to be done. Wish I had a picture of my old set up.
Sounds silly but I modified my 65 gallon and put in some LED lights with some DIY you can put any light in there. I put 2 vipar spectras for full coverage. It worked for 5 years but you will have to install a fan also.