Reading is free....... And you will need to do lots of it!!!! Don't listen to anything the Lfs tells you....... Read on here or Reef Central (highly suggest you create an account there) and then buy what you need. Things will only get more expensive with guessing, uninformed choices, and doing what the Lfs says to do.....
I can't believe you did not get sold a heater and thermometer......go get the proper test equipment (ammonia, nitrite, nitrate, ph) as well as a heater and thermometer.....I am assuming you have a hydrometer or refractometer to test salinity.....
As mentioned, a filter is ok but a skimmer is much more useful and easier to clean when dealing with a saltwater system.....
You will need to have approx. 1lb of LiveRock per gallon of water......
You need to test and monitor your tank for the parameters listed above because your tank is going to cycle......this needs to happen!
Bottom line is that guessing or asking people what is happening simply does not work....you need to test water in order to obtain actual readings.....you and us need these readings to figure out what is happening within the tank.....this will also give you a better understanding of how each element in your tank can affect it, how it affects it, and why it is affecting it..... Once tank gets going the testing procedures can be done less frequently because for one it will become much more stable, two, you will already know what has to be done in order to keep these parameters inline, and three if you notice something kind of out of whack then you may already know what is causing it from previous testing and knowledge......you see where I am going with this.....
READ, READ, READ, TEST, TEST, TEST, POST, POST, POST
Good luck and don't get discouraged......nobody dove into this head first and had amazing results and beautiful tanks right away......it takes years.....
I always tell people who seem kinda interested in the whole saltwater thing that the tank is not a picture you hang on the wall....it is a hobby and you will make it what you want.....
Please continue to post!!!! We love helping!!!!
Sent from my iPad using Tapatalk HD