Cardinals, rummy nose tetras and harlequin rasboras seem to be the fish of choice almost as an after thought in many planted aquariums. There are some good alternatives.
Planted aquariums can be stunning with schools of various “nano fish”. A good option is schools of six or more Ember Tetra, various small danios, Celestichthys margaritatus (Celestial Pearl ‘Danio’ or Galaxy ‘Rasbora’), Pseudomugil rainbowfish and small rasboras such as Emerald Dwarf, Chili and Pygmy. Other good fish which do not need to be in schools are Endler Livebearer, Scarlet Badis and white cloud mountain minnows.
If one has a large aquarium schools of rainbowfish are incredible as are schools of Congo Tetras. Both these fish are dull and not very attractive when small but are stunning as adults. They are both schooling fish which prefer to be in groups of at least six. Discus, rams, apistos and angelfish are the only cichlids that seem to go well in planted tanks. All the other cichlids love nothing better than to uproot every plant in an aquarium overnight.
A fully planted aquarium teeming with Blue Velvet or Cherry Red Shrimp (Neocaridina davidi) is simply beautiful. Shrimp are great in a low-tech planted aquarium and they come in all variations: white, yellow, red, blue and even striped. They multiply like rabbits. Note that the colors of the shrimp should never be mixed as dull grey green offspring will result.
It is important to remember the metabolism of an aquarium shrimp is much lower than that of a fish, so they need less food. Throw in a small shrimp or a piece of fish fillet on a string for one day once a week, then remove the uneaten portion. This allows the aquarium shrimp to eat their fill and avoids fouling the water.
Before adding a lot of fish to a planted aquarium one should read the following link:
Planted Aquariums in Depth
The following sections will tell you how to make a planted aquarium: