----- Original Message -----
From:
RS
Does any one know how much lighting would a 100-gal tank need in order to keep corals and other inverts?
What type of corals can I keep under two 40W Actinic Marine-Glo 7000K & two 40W Corallife 10,000K Daylights until I can upgrade? Will this lighting be OK for some corals like Leather-finger corals and Mushrooms?
From:
HL
A general "rule of thumb" is to have between 2.5 and 3.5 Watt of lighting per gallon of tank for "low light" inverts, such as Star Polyps, Mushroom Polyps, Leather corals, etc. For "high light" corals, such as most SPS types, anemones and clams, you will need around 5 to 7 Watt/gallon as a minimum.
This is not really a very accurate way of expressing light intensity, though, and you will have to look at the type of lights you want to use, and the depth of the tank, before making a final decision. Normal fluorescent lights are not really bright enough for practical use. As an example, I used a total of 8 x 38W-40W (~ 320 Watt, or ~5.8W/gal) normal fluorescent lamps (3 Tritons, 2 Blue Moons, 2 Marine Glow's and one "Daylight") on my 55 gallon tank, and this was not adequate for my anemone or any "high light" corals. I have since upgraded to 2x 150W metal halides, supplemented by 3x 38W fluorescents. Your proposed 4x 40W normal fluorescent lamps will only give you ~ 1.6W/gal, which IMHO is not enough for leather corals. If you place the mushrooms quite high up on the rocks, they should do OK, though.
From:
WS
I beg to disagree slightly about mushrooms.
Their lighting needs do vary according to species and some of the more coloured ones do not like very bright light. It can cause them to lose their colour. I have experienced this in my own tank where I have some blue mushrooms and some pink and green striped ones. Sorry I do not know the proper names. At first I placed them at the top of the tank because I have fluorescent lighting. They began to lose their colour and having read somewhere (I don't remember where), that lighting could cause this, I moved them further down. Their colour returned and they are now beginning to spread. I have 4 * 40 Watt fluorescents of various sorts
From:
HL
Disagree by all means, that's what makes these Forums so useful (and entertaining, sometimes). We all have different opinions, and have achieved success by quite different ways, so who's to say which method is the "true way...). 'Shrooms are low-light animals, comparatively speaking. That's why I felt they did stand a chance in this "low light" tank. Remember, we are talking about 4x 40W lamps on a 100 gallon tank here, giving ~ 1.6W/gallon. If I'm not mistaken, you have a 55 gallon tank, and with 4x 40W lamps, you in fact have ~ 3.2W/gal...
From: PG
Mushrooms are the main invert life in my tank. Didn't have much luck with stony corals, so decided to only keep what survived in my tanks. Some day I'll get a photo, but they have taken over my tanks... I'm going to see if the LFS will trade some for something that I want. Anyway, from my experience, the different varieties tend to move to the light conditions they like. Some stay right under the halides while others move lower in the tank. They are all reproducing so much that many are crowded out and fall to the bottom where they thrive although they are sometimes a little smaller. I don't really understand the lighting formulas. Please tell me what I have. Tank 1 is 150 gal, 28" deep X 22" X 4'11" with 2 metal halide 5500K, 2-48"-40 w Marine Glo and 1-48"-40 w Moon Glo. Tank 2 is 150 gal, 24" deep X 24" X 5" with 1-40 w -48"-50/50 and 3-48"-Marine Glo.
From:
MJ
HL, how did you get so much light on top of a 55 gal tank?
From:
HL
Quite simple, I just installed 8 tubes next to each other in the (home made) canopy. I even had 3 tubes mounted on the lid, which made it quite heavy (and bright) to lift. The ballasts were attached externally to the back of the canopy. I had quite good coralline algae growth, and the light was bright enough for my soft corals, and some LPS corals. However, I felt that it was still not bright enough for my carpet anemone or future SPS corals. The metal halides did make a difference to the carpet - it is now expanding larger, and has stopped moving around.