Live Rock and Decorations

[effishient]

Having now found this website AFTER purchasing lots of equipment for my new tank, I fear I may have "jumped the gun" a little, but hopefully I haven't wasted too much time or money. My current setup is a 55 gal w/a combination of "reef safe" sand and live sand, an emperor 400, a single powerhead, and a number of really beautiful ceramic coral decorations. I have no live rock and don't really have intentions of getting any because I don't think it will look very natural surrounded by all the colorful fake corals I have.
My intentions are to make this a fish-only tank which will eventually include half a dozen peaceful fish, a few crabs, a couple cleaner shrimp, and maybe a starfish or two.
Probably to the dismay of many, I took the advice of my LFS and am cycling my tank with several Mollies. I'm testing water regularly and the fish are doing fine after nearly three weeks.
My main question is, now that I've bought all this, how "necessary" is having live rock in an aquarium and has anyone else successfully set up a tank similar to mine?
Matt

 

[aarone]

LR is beneficial to every tank. It helps out with Bio-filtration (so you can ditch that Powerfilter after awhile). It also provides a diverse microfauna life for your tank. In FW you try to limit the number of organisms in the tank. In SW you want as many different types as you can. Go with the LR. It will benefit you greatly. Plus it looks very natural IMO vs. the fake corals.
aaron

 

[col]

If you can afford LR get it. I cannot afford much so I add as and when I can afford it.
It is not essential to a Fish only tank, but it is desirable and beneficial.

 

[dacia]

For a fish only tank, you don't need any live rock at all. It is just a matter of preference. You can have a great deal of filtration without the LR. Just make sure that you keep the sandbed healthy with the proper snails and such.
My 20 gallon FOWLR only has 7 pounds of LR, and it also has a coral decoration. (It is a dead coral, not a fake one) I think that they look good together. I bought the LR to supplement filtration, and I also found that I had some hitchhikers on it...of course, my hermits devoured the bristleworm.
Here is a picture of the tank that shows both the LR and coral:

 

[effishient]

That's a beautiful tank you got there! How many and of what type of snails/crabs should I get to keep my sandbed clean?
matt

 

[dacia]

For a 55 gallon tank I would recommend about 15 hermits and 15 snails. You should get a mixture of nassarius, cerith, and astrea snails, IMO. People have said that scarlet hermits are better to keep than bluelegs becuase they are less aggresive, but I have had no problems with my bluelegs.
Also, don't add all the cleaners at once. There might not be enough food to support them all. Buy a few, wait a while, add a fish and more cleaners, wait a while...