Over 2000 posts and your not sure you whether you have low lighting or not

sorry i couldnt resist
Yeah i have some in my tank as well, very nice plant, you must have ok lighting as it requires medium to high light for it to do well, its interesting if you do a google on it as its considered as a invasive weed in a lot of countries.
You probably have Cabomba Caroliniana, i think thats the most popular one, thats the one i have, it grows really fast if you give it enough light, i have 3 WPG and its growing really quickly.
To work out how much light you have over your tank, find out what wattage your light bulbs are, and then work out how many (US) gallons your tank holds, so for instance if you have a 20 watt light above your tank and your tank is 20 gallons then you have 1 watt of light per gallon or WPG.
Proper reflectors for your light fittings are the most economical way to upgrade your lighting, and are really a must if you want success with plants.
Yep its nescessary to add fertiliser, co2 will help at all levels of lighting but not a nescessity at lower light levels.
Hard to tell you a suitable foreground plant without knowing your setup, particularily your lighting or WPG.
