Saltwater lighting????

Question

I person at the local fish store said that a 20 watt bulb in a 29 gallon tank would be enough light to keep most soft corals and many anenomes. is this true? he also said that any higher of wattage and the algae would get out of control. (i have a slight algae problem now but just added 20 snails)
~THANKS~

So what I am really asking is:
What kind of standard florecent bulb would keep corals healthy. 29 gallon tank remember.

Answer 1

Don't believe what you hear from pet stores. I had a double fluorescent tube (40 watts) when I started my first saltwater tank, and I had a bubble-tip anemone (one of the easiest species to keep) go downhill quickly in a 20 gallon long.

You can't base this on wattage nor just on the wavelengths of the light. You have to look at the total package of the lighting system, wavelength, wattage, etc.

All wattage means is the amount of electric the system uses. If you've noticed the trends in home lighting, there are compact fluorescents that advertise their wattage (usually a low number) versus a much higher wattage of an incandescent light, even though both produce the same brightness. Chances are what you have is a standard hood with fluorescent tubes about an inch or so in diameter. That's what my double fluorescent hood had two of (one was a 10,000K, the other a 50/50 (mix of 10,000K and actinic), and it wasn't enough. I had to go "up" to a compact fluorescent system to keep the anemone alive (and this type is good for soft corals as well). I now use a Coralife twin tube compact fluorescent on the tank that uses 130 watts.

Another option is a T-5 system. The T-5 refers to the tube diameter - the ones you currently have are probably T-12 or T-8. The smaller the number, the more efficient the system at putting out high-intensity lighting which corals and anemones need for photosynthesis.

The very best are metal halides, but these use a lot of energy and produce a lot of heat, so these may also require that you get a chiller to keep the water at a proper temperature. There are also systems that combine metal halides with compact fluorescents and T-5s.

The Kelvin rating, or color temperature is also important to have wavelengths similar to what corals and anemones are exposed to on reefs that they're able to use for photosynthesis. A 10,000K is a bright white that simulates midday lighting under about 30 feet of seawater. Lower numbers (5000K and 6000K are too yellowish and higher numbers 18,000K go toward blue-violet) The actinic is a deep blue which simulates dawn and dusk lighting (which is needed by some corals to induce reproduction).

While lighting is a factor in algae growth, so are the nutrients in the water. Unfortunately, if you plan to keep corals and anemones, you can't cut back on lighting, so you need to focus on nutrient control. If you don't use one, a protein skimmer might help. Also, use reverse osmosis water to mix the saltwater. Tapwater can contain both nitrate and phosphate, both of which are plant (and algae) fertilizers. Be sure you don't overfeed. Do partial water changes weekly to keep the amount of dissolved wastes down. Some people use macroalgae (Caulerpa or Chaetomorpha) to compete with other algae, but you need to prune and remove excess algae or this could take over your tank. Having snails will help, but also consider adding some small hermit crabs (blue-legged or scarlets), reef-safe shrimp (peppermints), and perhaps a small brittlestar to help remove excess food and to help with algae removal.

Some additional info on lighting: http://www.americanaquariumproducts.com/Aquarium_Lighting.html
http://www.peteducation.com/article.cfm?cls=16&cat=1789&articleid=2689

on algae control: http://www.wetwebmedia.com/algaeconMar.htm
http://www.wetwebmedia.com/avoidingalgaeproblesm.htm - with info on lighting
http://www.wetwebmedia.com/nutrientcontrol.htm


ADDITION: For a standard fluorescent bulb - I wouldn't think any would keep most of the organisms you're asking about alive. Certainly not anemones (other than Aiptasia, which is a nuisance anemone), but there are a few non-photosynthetic corals that wouldn't need as bright of lighting. Sun polyps (Tubastrea) is one that comes to mind, but since they aren't photosynthetic, you have to feed them: http://www.bomani.com/sunpolyps.html

Tube anemones (http://www.tropicalfishoutlet.com/Invertspecies.asp?InvertSubCategoryID=16&InvertType= ) aren't photosynthetic (although they sometimes look like it with the "neon" coloring come have), but these aren't suitable for clownfish and will sting other fish and corals in the tank (and they can move to new locations in the tank, so you can't rely on them staying where you place them) and they can sting you when you're trying to clean unless you use aquarium gloves.

Answer 2

for corals u dont really base it off of watts.

you need either a 50/50 bulb or 10000K bulb and a blue atinitic bulb.

My lighting system is a nova t-5 lighting for 97 watts. for a 20 high.

Answer 3

I thought that about 5 watts per gallon was good for corals. But the depth of your tank is just as important. There are some good forums where you can ask experienced sw tankers these kinds of questions. I belong to reefsanctuary.com. They have gladly answered all of my questions so far.

Answer 4

Oh yeah suresounds great drive safely dont need a DUI do we!!>????