get a good book Anthony Calfo has a couple good ones and/or
Eric Borneman, r/c vendors or amazon.com.... the $30investment will reward you many times over. If you want corals/anemone's you will find that you don't need a bigger wet/dry filter, you should ditch it altogether. Your sand is fine, i would add more till its about 5-6 inches deep, in the long run this sand and the live rock will be you "filter". Anemone's require lots of lighting and a mature (at least one year) tank, along with very stable water parameters, not to say that its impossible, but try some easy corals first ( mushrooms, kenya tree, etc). I would try to find a local club or at least buddy up with someone in your area with some experience, especially about equipment selection, stocking suggestions, etc. Lots of times the experienced reefkeepers have old equipment collecting dust and are willign to sell it to a newbie for reasonable $ to get you started in the right direction.