You also need to think about mixing a better substrate in with your colored rocks you have now.
I did what you are currently doing. I just threw together a tank with some fish and decorations and without doing the proper research I introduced plants into the mix. I learned about minerals, lighting, and CO2 too late in the game to save the tank that I had. I now have a completely new tank with just plants. You have to give the plants time to settle in before you go putting fish in. And goldfish aren't good plant fish. IMHO they tend to dig around too much into the substrate and uproot plants.
Here is a good site for good deals on planted aquarium merchandise: www.kensfish.com I don't think you can beat Eco-Complete and Flourite bags being under $20.
Anyway, here is a post that Exie sent to me. Now all of it may not apply to you but remember, you are taking on a bigger task when you add live plants to the mix.
1) Tank, Stand, Placement
Pick a good size tank. Ten is small, the slightest imbalance will kill your fish. 29's are nice, and still cheap. Larger gets more labor intensive for maintenance, more money for larger lighters, more expensive for more plants and fish, etc. http://alysta.com/books/fishtank.htm <- Pick one with a nicely sized footprint to build in. Deep for aquascaping? Shallow for showcasing? Tall for tiered display? Long for fish to race? Small, large, short, fat, long, circular, square, corner-cut! So many. Plenty of work and decisions here.
2) Light, Lighting
You want plants. Especially shorter plants require bright light; more light can never hurt (assuming you have enough CO2 and nutrients, we'll get to there). More choices: Metal halide - somewhat pricy, big impact on electric bill, produce lots of heat. t5 florescent - more pricy, big impact on electric bill, not as much heat. LED - HUGE upfront cost, zero impact on electric bill, no heat (Most LEDs pay themselves off after roughly 9 years, depending on your electric Kw/H price). Go fake shopping, check prices. You need powerful stuff for most plants. Personally, I use some 10k lights that you'd find in a workshop; they clamp on my tank and use a bulb you'd see used outside as a floodlight. Cost was negligible from home depot, but have a decent electricity cost.
3) Substrate, including Soil Media
Too many to pick from! Ah! http://www.plantedtank.net/forums/sh...d.php?t=153412 Start here. Also, this is a time to start considering looks - the color and composition of your substrate can have a huge impact on your tank's final look! Consider looks, cost, maintenance, nutritional value, ease of plant growth, etc.
4) Filtration and Circulation
Hang on the back? A sump? Canister? In-tank filter? This comes down to personal choice. I like a sump set-up, as you can throw your extra equipment into it, it increases the total water volume of the tank (more water = better. Always), and it skims the top of the water for me. It's also hidden from view. Do some light reading about the options here, and then come back with questions.
As with all biological systems, live plants have minimal, maximal and ideal temperature ranges. There are cool, cold, warm and very warm tropical plants and of course you should research and select thermally compatible species to go together. "most" plants sold in aquarium stores are tropical, but do some research on each strain. Some are from S.E. Asia, some are from africa, south america, etc. All will have different wants from their heat and water qualities.
6) Water: preparation, treating, testing
Water, as they say, is a lot more than just H-2-O; and even if you could get "pure water" your plants and fishes couldn't live in it. Both need dissolved gases, minerals and other matter to survive and grow. You need to consider the source of the water. From your tap - cheap, easy, probably has ammonia, definitely has chlorine/chloramines, TDS (Total dissolved solids) is probably quite high. From the local fish store - perfect; r/o removes almost all TDS, no chemicals, and buffered to your pH/kH needs (but costs a lot more!).
Testing. Learn about the ammonia cycle http://www.thetropicaltank.co.uk/cycling2.htm, then buy an API test kit or prepare to make frequent trips to your LFS for them to test for you. Also, consider the fishless, pure ammonia cycle. It's more humane, and gives you more control.
7) Nutrients, including Carbon Dioxide
Ho Lee Sheets, now we get complicated. You need to start worrying about more than one thing here! Minerals will be added from your substrate, trace from your tap water (if you go that route), fish poop, and dosages from a bottle. Good luck learning this stuff (start off easy -trace minerals and extra iron) http://www.yamatogreen.com/plantnutrients101.htm
You also need CO2. You can go with a reactor system, which is messy, cheap (up front) and expensive (monthly) or a pressurized system which is clean, expensive (up front) and cheap (monthly). The pressurized CO2 system becomes cheaper than a reactor after about 6 months, depending on the cost of CO2 refills in your area. Also, the pressurized system can explode and horribly mutilate everything the room if you mess up. But hey, thats why you're taking it slow and reading about how to not mess up http://www.plantedtank.net/articles/Pressurized-CO2/19/
Finally, something we care about! Ideally you've planned, known all along which plant species you intended from the get go, all the way back to your tank purchase. If not, check out some common plants, google "asian aquarium plants" or any geographical answer and click around for awhile. Make sure your final mix of plants will all agree on temperature, light, chemical compatibility, water hardness, who is tall, who is short, who floats, etc. This will largely be personal prefference. There's no problem at all in posting a picture saying, "This looks awesome. what is it and what else can I grow with it?"
9) Planting, aquascaping
Real pros go so far as to prepare schematics detailing top and front layout views of what decor items and plants are to be placed where. Or not. There's a ton of advice available on thegreenmachine (a UK company) that details all the thought that goes into aquascaping. But be warned - even though this step is almost the last one, its the first to consider. If you mess this up - you don't like how this piece of wood looks, or this rock is too tall, or anything else, its VERY hard to re-do after you've moved on. Check out the green machine for some inspiration and lecturing. http://www.youtube.com/watch?v=wZDexLMZFrU&feature=plcp
Ongoing care of your aquarium garden should be a breeze by design. A few minutes a day to check on the temperature and CO2 bubbling, filter function, and sparse feeding of fishes. Weekly routines might include partial water changes, nutrient checking and adjustment, perhaps some clipping, snipping of plant over-growth. Longer term maintenance entails lighting lamp replacement, re-enrichment or replacement of substrate additives', to the yearly (or longer) total re-do.
WHAT YOU NEED TO DO TODAY
Keep your fish alive, and get rid of them when possible via selling or trading (assuming you don't want them in your final setup). Do not add stuff to the tank, at all.
To clean your filter media, do a partial water change of your tank, gently squeeze/rub the filter into the old tank water (the part you just drained) and then add it back into the filter.
I have that same filter. The media cartridge is balls and falls apart - replace it if you haven't in the last month (only if you still have fish).
Second, write a budget. Decide total cost you're willing to throw down initially, and how much you're willing to spend on your monthly maintenance bill. Wait 4 days. Look at the numbers, see if they are still reasonable. Wait 4 days. Show them to someone important to you, get their opinion. Wait 4 days. Look at them again, see if they are still reasonable. Repeat this process as needed until you are 100% sure of your budget. Then come back to us and share your monetary restrictions, your visions of tank-ness, and we'll work with you on what corners to cut (or if you're rich, what awesome swag to buy)