I can see the old car, don't worry.

Java moss is a fairly slow growing plant. It'll help, but only a little bit. The faster the plant grows, the more waste it eats. But also the more frequently you have to trim it, which is annoying. It's kind of a tradeoff. The fastest growing plants that double in size in a week need to be trimmed every single week if you want to keep them at one size. But Java moss, which doesn't grow very quickly at all, barely cleans your water. So, tradeoff. Personally I keep medium growing plants in the tank with a low bioload and fast growing plants in my no-filter Walstad style tank where the plants are the only filter. *shrugs* What plant you choose is 100% your own personal preference. Pick one you find pretty :)

If you're looking for a wide variety of plants to choose from, try aquabid.com and sweetaquatics.com
You've got gravel as a substrate, which is pure silicon dioxide. You might not have any luck getting rooted plants to grow. They don't do so well in gravel. Instead I'd recommend a plant that you can attach to a piece of wood, like java fern, anubias, bolbitis, and similar plants. Floating plants like duckweed, water lettuce, azolla, and ricciocarpus natans might also work. Ceratophyllum demersum is neat because it doesn't have roots and you can wrap it around a weight to get it to sink, but it's vulnerable to depleted water. Java fern, anubias, and bolbitis are all slow growers. If the nitrogen runs out in the water column they usually are okay. But if nitrate drops to 0 ppm in a tank with C. demersum it's starving and gasping and because it needs to grow so quickly to propagate itself (this is one of those plants that doubles itself every week in optimal conditions) if ammonia, nitrite, and nitrate all drop to 0 ppm then the C. demersum might melt and all die. The best way to keep C. demersum is to also own a test kit and to overfeed the fish whenever ammonia, nitrite, and nitrate all drop to 0 ppm.

If you have a digital camera that displays the light's spectrum or have $5 to buy a diffraction grating, it might be worth your time to take a peek at your light bulbs' spectrum. This is chlorophyll's absorption spectrum: http://upload.wikimedia.org/wikipedia/c ... ectra2.PNG You'll see that between 500 and 600 nanometers the line drops to zero. Plants can't absorb light energy that is that wavelength. They reflect it. That's why plants are green, because they reflect green light. If your light bulb is emitting energy in that region of the spectrum, it'll look bright in your tank but your plants won't be absorbing any energy, and they'll slowly starve to death. So look for a light that produces energy in the region from 350-500 and from 600-700 nanometers (blue and red). The plants will grow better.

Thank you again O!!

Natalie, this is my 75 gallon tank. Lol, I wanted natural gravel or sand but my other half wanted to keep the silly "canival rocks" as I call them, lol!!

I use my small take to quarintine new fish (right now I have some of my old fish in it waiting for my 75 gallon to fully cycle again)

I am going to check out those plants and see what I can come up with!!

Ha ha, yes, carnival gravel is a good name for it. Maybe if you showed your partner some of the photos of the beautiful, natural looking planted tanks on this website you could win her/him over!

Sorry, i realize there aren't a lot of reference points but that didn't look like a 75 gallon tank to me.

No problem Natalie!!

Thanks again O!! I think I'm going to try that out!! I really like the look of it!!
Very cool to see the roots!!

The surface area available on the filter media [sponge] is analogous to the number of houses in a town. The more homes available, the more people can move in. The more surface area, the more bacteria. Now this only applies to available surface area. If the sponge gets blocked with detritus and the water stops flowing over half of it, the surface area available to colonize decreases. So it may look like you have a sponge in your filter but because the water's not flowing through it, the bacteria aren't living there.
If you add a sponge to a filter and keep water flowing through it, you can increase your available surface area. You can also increase surface area by adding a second filter.

Tell me a little bit more about your filter. What model is it (do you have a picture?) and what sponges and stuff do you have inside it?

For example, I have an aquaclear filter and I stick the sponge that came with it and two Walmart synethetic sea sponges in it. http://www.mel-co-services.com/ebayimag ... filter.jpg and http://www.walmart.com/ip/The-Bath-Sour ... t/10322263 (without the net)
And I have live, growing plants.