The intensity required also depends on the depth of the tank used. Within reason, it is safe to say that if you are using fluorescent lights only, the more you can put over the tank, the better. Metal halide lighting is generally reserved for tanks greater than 20 inches in depth, but can be used on smaller tanks, again depending on the organisms one wishes to keep. Signs of inadequate lighting can include excessive vertical extension in animals such as mushroom anemones, lack of growth or stunted growth, poor colour, and darkening of the tissue followed by gradual lightening as the zooxanthellae die- off. It is very difficult to do lighting well on a limited budget unless you have access to used, industrial or bargain priced equipment.
Filtration is a rather simple consideration for reef aquaria.
You need at least some form. Most aquarists today are still using live rock and by itself, live rock, when healthy, will easily handle the biological filtering needs of the tank. When combined with a live sand substratum, you have all the biological filtration bases covered. You do NOT need to have a trickle filter for biological filtration, save your money. There are many good models out there designed for various size aquaria or if you are at all handy, you can build your own.