spongebob is right, absolutely right, with the do your homework, make sure that you are ready for plants and know as much as there is to know about them, substrate- you want at least three inches of something along the lines of eco-complete planting substrate. this can be expensive, 20lb bags run anywhere from 30-40 bucks depending on where you go, if you have a lfs, that you go to quite often they may give you a bit of a discount but i wouldn't count on that, secondly- filtration, you want to over filtrate your tank, nothing will be more helpful and beneficial, third- you want your tank to be at a stable temp of around 78-82 degrees for most live plants, fourth- make sure your tank is properly lighted, this i can't help you much with because i use a system i've developed for my specific need, but i can tell you that you are going to want high wattage full spectrum bulbs, maybe a double set of metal halide lamps would work for your 55 gal. fifth, make sure you choose your fish wisely, many many many many fish are omnivorous and will decimate your plant population in a very short time. these are just some suggestions to get you started. start slow and work up to perfection, if it isn't right do it over, if it isn't broke don't fix it.
hope this helps,
Brandonzzzz

UHU......HUH! OK WELL I WAS ON THE ROAD WITH WORK ALOT AND I JUST LANDED A JOB THAT WILL KEEP ME LOCAL AND I WAS CHANGING 25% OF THE WATER ONCE A MONTH BUT NOW I AM CHANGING 25% OF THE WATER EVERY OTHER WEEK. THAT SEEMS TO REALLY HELP MY TANK CLEANLINESS.
AS FAR AS THE LIGHTING I HAVE TWO 16 INCH 15WATTS FLORESCENT LAMPS SPANNING THE WITH OF THE INIRE TANK. I WOULD THINK THIS SHOULD BE ADEQUATE LIGHTING. DO YOU?
AS FAR AS FILTRATION I HAVE A WHISPER 30-60 THAT HANGS ON THE BACK OF THE TANK I AM THINKING I WANT TO GET ANOTHER ONE FOR THE OTHER SIDE OF THE TANK. I JUST INSTALLED A 12 BUBBLE STONE IN THE BACK CENTER OF THE TANK THE OTHER DAY FOR TWO REASONS ONE I WANTED BETTER WATER CIRCULATION AND TWO MY OXYGEN LEVELS WERE A LITTLE ON THE LOW SIDE IN THE MIDDLE OF MY CLEANING CYCLE.
NOW SPONGEBOB I SEE THE PIC OF YOUR TANK AND WOW THAT IS NICE, VERY CLEAN. YOU SAY YOU NEVER HAVE TO CLEAN YOUR ARTIFICIAL PLANTS. WHY DO YOU THINK YOUR PLANTS NEVER GET ICKY AND MINE DO?

the wattage should be fine just get some diff bulbs, one spectra max full spec and one flora-sun, this should be more than plenty for your sized tank, extra filtration never hurts, also i forgot to ask how long do you have your lights on per day? this could be part of the cause for the algae growth, too much light can have an effect on algae growth, if you cut down to roughly twelve hours or a little under depending on the fish you keep, just think about how much daylight they would have in their natural environment and stick with that, and you should do just fine.

I have a $10 dollar timer plug for my lights... and they are set to go on around 5 pm and turn off around 11 pm (so roughly six hours). I don't have the tank near any direct sunlight... and when I had my lights on for any longer than 7 hours i would get bad algae, so i bought the timer and i havent had any problems since then. For sure this is your issue, I would leave your lights on for a max of 7-8 hours, less if you see algae taking over (some few amount will grow, but very slight which you can also then control with your water quality). It depends on how much sunlight you get, if you dont get much you can leave it on for a bit longer, but try less first as opposed to more as its hard to clean algae.

Another element that adds to algae is water quality. I just used an algaecide to get rid of a green water algae bloom (which was teh result of excess nutrients from 6 fish i added at once)... it worked like a charm, but my nitrite levels were deadly for a few days after as i did water changes every day of 25% until they reached zero, so try to stay away from that product, you shouldnt have to use it except in extreme cases, and if you do you have to closely watch your water levels (ammonia, nitrite, nitrate). You can get a liquid test kit for these by API.

Try the timer and you will see a huge difference in the water quality. Depending on the algae you got, your plants might need replacing, as some are impossible to clean certain algae off.

As for the filteration, I would personally suggest a gph of 10 times your tank size if not more. Personally I have two filters on my 20 gallon, which move close to 240 gph (or 12 times my tank size). You say you have a whisper 30-60... im not sure of the gph, but a whisper 60 has 330 gph... which is about 5-6 times your tank size... i would add another of similar size, but check your current filter's gph and add accordingly. It will make your water much clearer and healthier for the fish, you will notice them much happier and active. At that point you can look into adding other media for different uses.

Good luck, let us know how it goes