Sea Hare Question
 

So Ive had this sea hare for a month or two now, got him to clean up my HA and he totally has eliminated it.

Now I know they are toxic if they die, but we still have lots of other algaes growing. What do you guys think I should do with him? He doesnt seem to eat the other algae but still "works over" the rocks. I just dont want him to be malnourished.

Over time, I lost 2 sea hares, due to starvation. Usually others can use his services, so pass him along.

If she has finished the hairalgae and is trying to re scrape the rocks she is starving to death.
Get some of those sinking spirulina pellets or tie some nori to a rock and sink it so it can get something to eat.
Offer her here to another reefer that has a hair algae problem or return it to the lfs who will find another good home for her.
Thanks for asking.

Even if she is the only one in a 165G theres still likely not enough algae growth for her?

no - they only eat hair algae and a lot of it. Once it's gone, it's time to pass the seahare along.