Plants for the aquarium
Plants. This folder considers practical aspects of plants and their requirements. Esthetic considerations about ways of using plants are part of the "Aquascaping" folder.
Some specialized aquarium situations require a tank without plants. Many feisty and territorial pit-spawning Central American cichlids, for example, intuitively root out plants in order to clear an opening that they can securely patrol. Common Plecos (Hypancistrus spp), get so large they smash plants just by thrashing around, like an airedale in a tulip bed. Discus thrive in blackwater conditions at temperatures in the low to mid-80s that stress plants. Malawi and especially Tanganyikan cichlids need higher pH values than most plants enjoy. Though Vallisneria can sometimes be part of their native environment, in the aquarium they don't treat plants kindly, as a rule. But there are exceptions. George Reclos has worked out the techniques for a glorious planted mbuna tank. It's essential to diffuse supplementary CO2, he finds, for the high pH all but eliminates free carbon dioxide in such alkaline water. He explains it to you at Malawi Cichlid Homepage with an impressive photo, too.
All the more ordinary aquarium environments profit from the stability and the constant nutrient recycling that plants contribute. When J. Shirley Hibberd introduced aquarium-keeping to the general British public in The Aquarium and Water Cabinet (1856), the plants came first: "it is a water garden, in which we cultivate choice plants, and it is also in some sort a menagerie..." You may not have grown aquarium plants before, or you may have tried Cabomba or Elodea that disintegrated within weeks. These two floating plants are plentiful and cheap in the US because they do well in Florida's limy waters; they need high light levels, cool temperatures and alkaline water, and they never did very well for me.
But, fear not! There are many other aquarium plants so easy to grow that you can handle them, even if your houseplant experience is limited to a philodendron. Start with the easy plants. Even if you never get beyond some ferns, Java Moss and Anubias, you can still have a handsome natural environment.