I plan to get a 28 gallon biocube... my question is what can I stock? I want to do live rock, an anemone because I think they're pretty cool, a shrimp or crab or some kind of bottom feeder... my question is what fish? Do saltwater fish get as big as cichlids? I always see small ones in pet stores. How many fish could I keep in a 28 with those conditions mentioned above? What kinds could I keep? I'm new to salt and want to make sure I'm going to like what I get.

28 gallon can hold 1 or 2 small fish like clowns not much else. As far as anemone they need a well established very clean tank I would suggest you wait 6 months after you have set up the tank. In saltwater you use what is known as a clean up crew which consists of snails ,crabs, and other very small inverts that will dig in the sand. This is very basic info as I haven't had a salt tank in many years.

My salt tank is 29 gallon so basically the same as what you are looking at just dimensionally different. I have about 45 lbs of live rock in mine and looking to add more. The more rock the better the bio filtration. Definitely get a nice clean up crew...hermit crabs, snails, maybe emerald crabs, ... I have a coral banded shrimp and a sand sifting star too. Fish...oh my! Yes some get huge!!! Do some research and see what you like and the size that they will be when older. First tip...don't cycle with a damsel unless you want that damsel forever and they can be downright mean little fish. My only fish in my tank are two ocellaris clowns (one orange & one black) and a firefish. I could add another fish or two like a lawnmower blenny (but I had one and it died so didnt' replace it). Saltwater fish don't follow the inch per gallon rule at all. They are more like inch per ten gallon if you need to have a rule like that to look at.

Also if you include live rock from the start you may not see an actual cycle. I never did. I started with about 15 lbs of live rock and the next week added another 10-12# piece. I never had a cycle because of all the life on my rock. Make sure also that you get cured rock because if you get uncured you will have to go through all the hassle of curing the rock.

I am rambling, but if you need more advice let me know. Being that I just set up my first one 13 months ago I am still fresh with everything that I went through to get it right! :)

...............1st of all!!!!! those nano cubes are perfect for starting off in SW
the 1st think i can tel you bout SW is THAT YOU HAVE TO READ!!!!!!!!!! iv been reading bout keeping SW for bout a year now and im still reading!! still dont currently have one (YET:) ) but yea study every lil thing b4 you go for it!

youll need 1-1.5lbs of Live Rock per gal!
same with sand!
bio cubes are AIO (all in one) tanks so youll be ok on equipment!
depending on how much fish your gona house! youll need a skimmer! but if your goin with like 2-3 youll be fine with a water change every week dont lag it!
you can have a cpl fish in this tank
you can have like a pair of clowns, cleaner shrimp, and some type of goby!!! if you want somthing cool i would suggest getting aq Yellow Watchmen Goby and a Pistol shrimp! they actually pair up and live in the same burrow!!! theyre awsome lookk em up!

all those fish including you CUC (clean up crew) would be straight up ENOUGH fish for that tank!
for the anemonie itll be a cpl months for you to get! tank has to really cycle b4 adding anything like that!

do you plan on going reef? or Fish only?

what is reef as opposed to live rock?

Reef is ya know corals clams awsome fish and such. all the nice prettyfull looking stuff colors and what not!
FOWLR (Fish Only With Live Rock) is literally just fish and rock! ehh.........

It really isn't reef as opposed to live rock. Live Rock is incorporated in most all saltwater setups. It would be reef vs fish only w/live rock. Reef has all of the corals & clams that most people think of when they think saltwater. But you can have a nice FOWLR (fish only w/live rock) setup as well. They require less intense lighting than it would if you went reef. Some people start out as FOWLR to get the feel of maintaining the salt parameters before spending money on the corals and whatnots to have them perish due to lack of experience. Myself...I dove into the reef setup as that was my dream. I am still building mine slowly since it is costly and I buy corals that fit my needs at the cheapest prices that I can. I love to buy small frags for under $10 cuz I can watch them grow into my tank and I am not devastated if they die. I have only killed two corals since I started 13 months ago BTW. And both were due to being too close to the watermelon mushroom in my tank. I guess that one is a killer shroom! LOL

so with this lighting is it possible to have an anemone in my tank?

105 watt 10,000°K/7,100°K compact fluorescent lighting

gobies are pretty cool and stay small.. look at mandarin goby or watchman goby yellow etc.

Mandarin gobies require pods to eat unless you are lucky enough to get one that eats prepared foods. They are not for a newly established beginner tank. The yellow watchman goby would be more suitable though.