on my way

I don't think your losses have to do with the algae bloom or the adding of LR.
More than likely your anemone died because your tank is to young for it. If I'm correct you said you have about 6 months with the tank, take a month of cycling that makes it 5 plus a month or 2 it stayed on your tank..

Anemones shouldn't be in a tank younger than a year IME.
And if your anemone died when you had the fish in there, then that's your cause of fish loss.

 

skimmer and more rocks soon. My 55g has livesand at the bottom no gravel

 

And this is why i'm so glad I found this site. The person who sold me the anemones neglected to tell me this, or maybe they assumed I knew what I was doing :-[

 

And yes a skimmer is a good idea.. They are not nessesay though.. IMO
I don't have a skimmer at the moment and everything is running smoothly. Although a skimmer should make it even better.