Hello,
Let me start by first saying that you are not taking up alot of our time!!! We are here for enjoyment as well as learning and offering experiences, successes and failures!
Moreover, you will not be able to pick up all the information necessary to make you 100% successful, as their is too much available information as well as alot of trial and error. This being said, learning from your experiences or that of fellow reefers(good or bad) will enable you become more successful and better prepared to deal with the myriad of variables associated with the marine hobby and the health, growth and brillance of your livestock!
Ok, time to answer your questions as you begin your journey towards a successful marine biotope...
Your tanks water parameters are going to be all over the place during the cycling phase of your tank during the infancy stage. Keep testing your water to track the progress of your tanks cycle.
A skimmer is an valued piece of equipment, IMO! I would run the skimmer during the cycling phase, to rid contaminants and pollutants. As for the water changes, I would NOT perform a water change during the cycling phase. After the cycling phase, I would perform a small water change every week to replace trace elements, and dillute contaminants and pollutants such as dissolved organics and particants.
The issue of lighting can be a complex one! However, to simply put it-you need to determine if you want to add corals, then break it down further as to the genera and family of species you wish to keep. This part of the aquarium concept can make or break you with regards to the success of your corals and Tridacna Clams, especially! Take the time to familiarize yourself with the terminology, types of lighting, kelvin, lux etc.! It will help you significantly and you will be glad you did!
Their is an influx of books, articles and online material to help you with your coral and invert question. I have also written some on AC(People's Media Content)
An Introduction to the Marine Aquarium Hobby (Part 1) - Associated Content An Introduction to the Marine Aquarium Hobby (Part 2) - Associated Content Substrate, Aquascaping and a Deep Sand Bed (DSB)? - Associated Content Great Aquarium Corals and the Ease of Keeping Them - Associated Content
Rock can be dead or alive and if you start off with just a couple pieces of live rock and the rest is dead initially, the dead rock will become alive with a diverse and desireable population of bacteria, polychaete worms, micro and microinfauna etc. soon enough!
If you add some live rock later on after your tank has cyled through, you may run the risk of a ammonia, nitrite and nitrate spike depending on the size of your tank and the amount of live rock you add(and amount of die-off associated with it).
The spots are often times diatoms, which are common, especially with a new tank. They should go away just as quick as they appeared. Cyanobacteria and nuisance micro algaes may pop up as well. Decreased feeding, possibly a phosphate reactor or remover and a carbon additive will help you to keep your nutrient level down to deter these problematic flora from taking over your tank...
INO, hold off on the cannister filter as that is not a necessity! As long as you have biological and chemical filtration with the skimmer complimentation-you will be fine...
Spend the time on a good book(s) regarding the marine environment and hobby and that of the living animals and plantlife associated with a reef/marine biotope!!!
Take your time to do it right from the get-go!!! The more you know and the better prepared and confident you are the better off you will be as well as that of the living organisms within your closed system environment...
Best of luck and I hope I have beeen able to help you out somewhat, without getting to verbose!!!!!
