Here's a bulb that will cost you $20, including shipping to your door. I don't sell it; there is a link to where you can buy it on the page. It is NOT at Home Depot - read the details:
Once a month, you should cull 25% of the macro algae to encourage more growth. Use scissors to cut the plant rather than ripping it apart, because the scissors pinch the vines shut as they cut through, where a ripped strand will leak that fluid into the water unfortunately.
The only trimming I would do is dead stuff. I like a clean system.