Lighting
Undisputedly the most important factor to plant care success. I will review the pros and cons of each lighting types currently in use at Sweet Aquatics. There is a general rule of thumb to use 2-3 watts of light per gallon. In my opinion this rule is to vague. Depending on light type being used and height of a tank this rule does not apply. Plants requiring high light can be grown successfully in short tanks using low wattage fluorescent fixtures.
The use of the metal halides, and/or Power Compact Fluorescent greatly defies the rule of thumb, because of the high lumen output and wide spectrum range. Plants can be grown using a low wattage fixture type even in the tall tanks.
Lighting Types
Natural Sunlight
Pros: Cost is free. Sufficient light and spectrum range to grow any plant.
Cons: Promotes explosive algae growth. Not always convenient for aquarium placement. Uncontrollable.
Though free. Natural light is too unpredictable and unreliable. Great success can be had when plants are grown in outdoor containers.
Fluorescent
Pros: Low cost. Wide range of bulb choices. Readily available. When used on short tanks high light plants can be grown. Can be rewired for higher light output.
Cons: Some bulbs have short life span. Not adequate for large tanks. Can limit plant selection.
Fluorescents are the most widely used and readily available. Great for all tanks up to 55 gallons.
Power Compact Fluorescents
Pros: Great for larger tanks. Lower cost than MH, VHO with about the same results. Wide range of bulbs. Most recommended for keeping plants.
Cons: Some bulbs have short life span. Can be costly. High heat output.
Though more expensive than florescent, PCF's are very cost effective and are cheaper than the other light options for larger tanks. PCF's produce a lot of heat output, but usually have built in ventilation fans.
Metal Halides
Pros: Great for big tanks. The closest light to natural sunlight available. Long bulb life, has a wide color spectrum.
Cons: Expensive to buy. Fixture gets very hot. Some plants cannot take the intense light output.
Though expensive. Metal halides provide the best light intensity and spectrum to grow any plant. The intense color of red plants produced is reward enough. Care must be taken when using MH. The fixtures become hot and must be ventilated. In addition fixtures must be suspended a distance over the tank due to water temp increase. Algae blooms can also be a problem, if insufficient plant numbers are present.
Overall, the above descriptions reflect my personal experience. Of the lighting choices available, the power compacts are most recommended for the flexibility and ease of use. Power compacts yield the least margin for error. They can sustain high and low light plants and are least likely to promote algae blooms. For more experienced hobbyist I recommend metal halides. The growth rates and overall look are second to none. Fluorescent cannot be ruled out entirely, as they have their place. Myself and others have had great success with twin tube fluorescents. They work best on tanks under 55 gallons or tanks less than 18" high.
