I've been keeping fish for about 15 years and plants for about 5 years now, but I'll admit I'm very uneducated about the plants. I want to start focusing more on them and having a better planted tank and I'm looking for some advice 
I have a 20 gallon right now with tetras, cories and guppies. It has a flourscent bulb (I'll check on the wattage, but I don't think it's all that much, I got it at my lfs and it was recommended for a planted tank) and it recieves sunlight in the afternoons, but not intensely. The substrate is fine gravel on the bottom, and larger river stones on top. The ammonia and nitrite are zero, nitrate is typically around 15 and the pH is low, about 6.2. There is driftwood in there which contributes to that. The gH is good but the kH out of the tap is very low, so I buffer it. The filter is a penguine biowheel.
There is a lot of lacey java fern in there, which grows great; and an Amazon sword that I've had for years. My problem is the sword, the poor thing looks horrible. It's coated in black algae which is nearly impossible to remove without ripping the leaves, and lately is just looks limp and sad. It still grows a lot of new leaves, but I want to try and make it healthier. I'd also like to add more background plants, but I think I need to figure out how to care for them first
What should I do for this tank? I've heard that flourish is a good idea, should I also consider CO2? Ideally I'd like to keep things simple but still have a few nice plants. It's a bit crowded as it is, but I can always remove some rock to make room for more plants.
I have a 20 gallon right now with tetras, cories and guppies. It has a flourscent bulb (I'll check on the wattage, but I don't think it's all that much, I got it at my lfs and it was recommended for a planted tank) and it recieves sunlight in the afternoons, but not intensely. The substrate is fine gravel on the bottom, and larger river stones on top. The ammonia and nitrite are zero, nitrate is typically around 15 and the pH is low, about 6.2. There is driftwood in there which contributes to that. The gH is good but the kH out of the tap is very low, so I buffer it. The filter is a penguine biowheel.
There is a lot of lacey java fern in there, which grows great; and an Amazon sword that I've had for years. My problem is the sword, the poor thing looks horrible. It's coated in black algae which is nearly impossible to remove without ripping the leaves, and lately is just looks limp and sad. It still grows a lot of new leaves, but I want to try and make it healthier. I'd also like to add more background plants, but I think I need to figure out how to care for them first
What should I do for this tank? I've heard that flourish is a good idea, should I also consider CO2? Ideally I'd like to keep things simple but still have a few nice plants. It's a bit crowded as it is, but I can always remove some rock to make room for more plants.
