Last question (I promise
Do you use RO water?
I like Premium Aquatics cleaners the best (
www.premiumaquatics.com)
In my 24 gallon Nano Cube I have
Nassarius Snails (Great for the sandbed, get 5)
Nerite Snails (Small but work on the tank glass, sandbed & rock, get 3-5)
Baha Hermits (Love these guys, they do an awesome job, best hermit you can get - Avoid the Blue Leg Hermits, they are monsters - get 4-5)
Cernith Snails (Worthless IMO but I only have 3, maybe I don't have enough in my tank. Try a few and see if you like them)
Margarita Snail (Likes to clean the rock, big, strong snail, get 1)
Stomatella Snails - Not sold at PA, might have luck finding someone locally that has some. Mine are nocturnal and reproduce like crazy. Likes to clean the tank glass and rocks. Do some reserch before adding them and see if they are for you).
The main thing to do is take your time (and get rid of those damsels imo). A clown is just as hardy as a damsel and they aren't as big of jerks. Also having 1 clown in your tank means less waste than 2 damsels. Once your tank gets established you can get another little fish like a firefish, Royal Gramma, Pseudochromis or Naso Tang (just kidding about that last one

)
Diatoms will go away as your tank matures and as your cleaner crew does their job.
If anyone tells you to get a sand sifting star, cuke, conch or other sand sifting critter that will outgrow your tank within a day slap them
Do you have anything like Chemi-pure or Purigen in the back chambers? I use both. Go to Dr. Foster & Smiths website and read about them. Purigen makes my water crystal clear.