1. Make sure you have sufficient lighting, you want around 40w of light. If your hood holds a single light bulb then it doesn't have enough lighting. A cheap way to have enough lighting is to replace the hood with an incandescent hood that allows you to screw in the energy saver CFL lights, then buy a pair of 20-24w "daylight" CFL lights. Total cost should be around $25-$40.
2. Plant choice. Elodea Crispa is the pond version of anacharis and is a cold water plant. There is a tropical version of anacharis that will be fine in 78d, Elodea Densa. Wedging it under ornaments or sim0ply burying the stems in the gravel is fine. You have other options, common low light plants are:
Java fern & moss - tie to ornaments, driftwood, stones.
Anubias (nana, bartreri, coffiefolia, etc) - like java plants, tie to something.
Hornwort - wedge or tie to something.
Aquatic clover (marsilea) - separate the small plantlets and plant in the gravel.
Crypts (wendtii, lucens, lutea, etc) - plant in the substrate.
3. Buy lots of plants. Scary prospect for beginners but you will have a MUCH easier time fighting algae with more plants. This is probably the biggest mistakes that beginners make, not starting with enough plants.
4. Nutrient requirements in a low light setup are low enough that you may not need to dose additional ferts, but it's a good idea to have some on hand. I'd recommend getting a bottle of Seachem's Flourish (the comprehensive one) and Flourish Excel and only dose if your plants don't look healthy.
