An easy, undemanding plant to grow in my high light, high tech tank. However "dwarf" is relative. After a couple of months many of the plants were easily over a foot tall.
Some hobbyists consider this plant to be invasive. I love watching the runners grow and spread! It may leave the top half of the tank for the fish to swim. This is a great way for beginner's to build some confidence in the hobby and start off. Make sure your substrate granules are small enough so when you 'thin out' your Dwarf Sagittaria, the roots come out clean and intact to give away to your fellow hobbyists or local fish store.
I have a 10 gallon tank with a gravel substrate. The dwarf sag was slowly melting away over the first six months I'd had it. Then, someone told me that I should try a different substrate OR root tabs. So, I added a couple root tabs. In a week's time, I had new plants growing. All of mine have stayed under 3 inches tall. I have two 10W "mini" flourescent bulbs.
Dwarf saggitaria is out of the limelight because of Glosso, Hairgrass and HC but it is a splendid foreground plant, easy for the beginner and makes a better carpet than the photos imply. It spreads quickly and is very undemanding. You do have to pull out the tallest leaves for foreground planting, so it is best in medium to large sized tanks.
I love my Dwarf Sag. I started with 7 plants about 3 weeks ago and now I have 9. I can't wait to see how it responds with more light, better substrate(Eco Complete vs plain ole gravel), CO2 and ferts. Well, I learned that this stuff hates to be moved. It shed quite a few leaves but now after about 2 weeks, it's bouncing back nicely. It's now rooted in soil.
I love this plant. I started with 7 dwarf sags last February and after a month, it multiplied 10x! I was amazed how this plant propagate. Now, I can say that my tank has a nice carpet of dwarf sagittaria... :) http://www.plantedtank.net/forums/yourtanks.php?do=view