debraggery

I recently purchased an established 20 gallon nano-reef tank and I'm loving it and learning about it at the same time! I have so much to learn, as many of you have in the past. My water parameters seem to be pretty well established, salinity at about 1.024, pH is around 8, Calcium and hardness are within good levels for a reef aquarium and my only problems seem to be slightly elevated phosphates with nitrates within acceptable levels.
I have recently caused the death of a BTA so I'm trying to determine the reason for that and am attempting to keep things well-stabilized. My next issue is a diatom bloom. After reading several threads in the forum, I'm PRAYING it's not "dino"! Bought more CUC and hoping for the best, reducing light time hours.
Another issue that bugs the CRAP outta me is bristleworms. I'm trying to locate a Hector's Goby in hopes that he'll help me limit the population. What are your thoughts about bristleworms? I've read that they're not bad but it seems I have a LOT of them!