Yes, as James says with that much light you'll need CO2. I have the same amount of T5 light in my 29 gallon and it would be algae soup without CO2 and ferts. The idea of adding co2 and ferts to a high light tank is to get the plants growing to a point that they out compete the algae for nutrients. I wouldn't use actinic bulbs either as all they do is promote more algae growth.

You can make a simple DIY CO2 reactor for a small tank like that by using a 2L soda bottle filled with yeast, sugar, and water (some say baking soda too, though I don't use it). If you look up DIY Co2, you'll find tons of recipes and instructions for making your own system. A power head would be a great way to diffuse the co2 into your tank. Flow is not critical in a planted tank as it is SW reef tanks.

The problem with plain gravel is that plants don't really like to root in it very well and you could find yourself replanting them a lot! It also needs to be enriched with fertilizer tabs every few months.

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29 Gallon Planted
1 Angelfish; 2 German Blue Rams; 11 Rasbora Boraptensis; 3 Khuli Loaches, 1 BN Pleco

20 Gallon Planted
2 German Blue Rams; 5 Corydoras Paleatus; 4 Otocinclus Catfish; Amano Shrimp

5.5 Gallon
Betta, Some plants.