You know when you go to the beach and you see the foam building up along certain places. Well this "foam" is excess protein that builds up, which is what happens in the home aquarium. The excess protein is very damaging to the fish and invertebrates. To solve this solution, you will need a protein skimmer. A protein skimmer simply removes the protein on the top of the water and puts it into a collection cup where you eventually clean it out.
A good typical protein skimmer can cost you around $150. In my personal experience, I have went cheap and kept thinking that it will work, but the saying "You get what you pay for" is never used better when buying a protein skimmer. So buying one that is rated for about 2.5x the aquarium size is the best. So for quality and long time usage, you will end up buying one for around $200.
Here are three protein skimmers that work well in the saltwater aquarium.
Now an aquarium can survive without a protein skimmer if you purchase an aquaripure. This unique type of filter uses a bacteria to convert the nitrate atoms into nitrogen gas and releases it into the air. Here is the website for the aquaripure nitrate removing filter:
If you choose to not purchase a protein skimmer, then doing double water changes and having a power head break the surface tension, then you will most likely be fine.
Your current filters are just fine and using a carbon cartridge will do the aquarium justice.
So now that filtration is out of the way, then lets move onto maintenance.
As far as maintenance goes, you will just need to change the filter and clean the protein skimmer cup every month. Or two weeks if the tank is looking pretty gross. Water changes are virtually impossible to skip if you want a healthy system. But due to the greatness of an aquaripure filter, then you will not need them if you own and maintain one. (Maintaining an aquaripure filter is easy and you can read the instruction booklet if you purchase one.) But if you don't 25?eekly water changes are required. Along with the fact that you need to pre-cycle the water before hand. So having an extra barrel of garbage can full of saltwater, with a powerhead for circulation, then you will just have to drain the tank and then re-fill it. Oh and when the water level drops and you need to add some more water. Just add fresh water, because the salt doesn't evaporate and the salinity of the water will rise, so adding the fresh water will neutralize this. But obviously during a water change out then you need to replace it with salt water with the same salinity and temperature. (Salinity is salt content [about 1.022-1.026 is a good salt range]) When purchasing salt, try and buy one starter pack. This will give you a hydrometer (salinity and specific gravity reader) and some test kits. Then if you need more, just simply buy extra salt to finish the job. The best brand of salt is probably Instant Ocean, but they usually don't sell starter kits so buy the Red Sea starter kit for best success.
So on to the fun stuff. A good basic starter fish is either a damsel or chromis ($4-5 each) And once your aquarium is up and running for 2 months, you can try these fish. And if they are a success then you can move onto more kinds of fish such as clownfish ($13-16 each) and so on. After about 4 months of continuous success then you can move on to some more vibrant and beautiful fish.
Dwarf Angelfish ($20-50 each)
Butterfly Fish ($20-65)