Well, the good part is that.. even if you have a densely planted tank in your 40 gallon, you don't need CO2 gas mainly because it's just to help with the photosynthesis cycle. By creating glucose.I would like to put some live plants in my 40gal. I have just normal pebbles as substrate.And if possible i would not like to do the co2 way. Whats plants are really easy to keep. Thanks
I see. So you use low lighting for low light plants right?I have kept many a low-light tank, and the very easiest way to start out is with the plants mentioned above, except that purple waffle is a bog plant and is not an aquatic plant - they will not do well long-term submerged. Also avoid plants like Dracaena and Liriope, commonly sold in pet shops as aquarium plants, both of which are terrestrials.
I just recently took down my 55 with java fern (regular and lace), Cryptocorine walkerii, Anubias nana, java moss, and aquatic lily. This tank basically took care of itself and I did nothing but water changes and fed the fish, with lush plant growth. It is a great way to start out. Other plants require more lighting, which will mean fertilizers and CO2 to combat the algae that will grow with increased lighting.
You can achieve a nice easy low-light setup with about 1.5 -1.7 watts per gallon (roughly - this rule has variables, but on a 40g you can just calculate this by the wattage of the fluorescent bulbs you have).