Please Help !!!

Nicole,
I would also suggest doing a water change that will also help your tank.
But there are still problems you have here. I see you have a blue manderin, yes they are cute fish but a 4 month old 29 gallon tank is not for him. These guys need atleast 150 pounds of live rock to keep them happy.
These guys tend to starve to death slowly in a small tanks, the larger the tank, and more live rock the more food is supplied for them.
I think part of the problem you had here was over crowding as well. To many fish for a tank this size. You may be fine with the 2 clowns, i keep fewer creatures in my 55 gallon tank. If you can, i recommend taking your manderin back to the lfs and get some store credit. You will need it in the future.
From what I am gathering here as well is you may need to get more live rock. For a tank this size, you will do best with 40-60 pounds of it. Make sure its cured when you pick it up from the petstore. Also, as others made mention, hook up that skimmer it will help some of this headache you have here.
I think also part of the reason why the starfish died beside bad water quality, is lack of food. These guys are scavangers and will eat the algae off the tank and rock, it probably was in competion with the urchins. But don't quote me on that, i am not a starfish expert.
But like I said, number one thing to do is get a water change going. Some local fish shops do sell premixed salt water (you usually have to bring in yoru own containers for this) pick up 5-10 gallons and do a 5 gallon water change, keep an eye on it, and then do another in a day or so.
 
I also recommend some books to read as well. To many people jump in the hobby with out reading books. I always recommend the reading. :)
Natural Reef Aquariums: Simplified Approaches to Creating Living Saltwater Microcosms by John Tullock, John H. Tullock (Paperback)
from Amazon $23.07

I believe this is out of print but you may stumble on it.
The Reef Tank Owner's Manual: A Practical Guide to Establishing and Maintaining a Coral Reef Aquarium (Hardcover)
by John H. Tullock


Your First Marine Aquarium: Everything About Setting Up a Marine Aquarium, Aquarium Conditions and Maintenence, and Selecting Fish and Invertebrates (Barron's Complete Pet Owner's Manuals) by John H. Tullock


The New Marine Aquarium: Step-By-Step Setup & Stocking Guide by Michael S. Paletta, et al (Paperback)
From Amazon $13.57

If you ever go into corals, I recommend these, unless you can get them from the library, then go ahead and read them. They have great info for reef and non reef tanks.

The Reef Aquarium: A Comprehensive Guide to the Identification and Care of Tropical Marine Invertebrates (Volume 1) by J. Charles Delbeek,Julian Sprung

The Reef Aquarium: A Comprehensive Guide to the Identification and Care of Tropical Marine Invertebrates (Vol 2) by Julian Sprung, J. Charles Delbeek
 
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