New to Hobby, Inherited tank with new house, boy do I need help.

[ponokareefer]

If when you are vacuuming your substrate, and it is so dirty that you can't see the bottom of the bucket, I'd say that is a major problem. As another reefer pointed out, I would start pulling out a handful a week until it is gone.
Also, are your lights only actinic, or 20K? The picture just seems very blue. If you are only running actinic, you will want to get a few different bulbs. With regards to bulbs, how old are they? Old bulbs can cause algae problems in an aquarium. I will let people who have T5's chime in on how often you should change them out, as I have metal halides. If you don't know the age of some of them, I would switch them out.