coral lighting

[devgru]

Hello evryone,
This might seem redundant but I'll ask anyway just to see what feedback I'll stir up.

Every website that sells coral states a Watts Per Gallon as that particular specimens requirements.Why cant they/we use Watts Per Specimen?
I have a 125g tank with leathers mushrooms and a few softies.If I wanted to add 1 oregon tourtosa,in doing the math I would require 7-10 WPG?just for that 1 coral?

I was wanting to add a 20L below my 125g display and above my 125g sump/fuge setup to start adding coral to until I revamp my display tank lighting.Would the WPG work in this scenario?If so I could just add 2 PC(65w ea.) or slighlty higher and satisfy the coral in the 20L?

Currently on the display I have 1x175w MH,2x65w PC and 2x32w NO.Everything except the Xenia is doing great.They disappered a month ago but I can see "heads" forming again so I think their better.My shrooms are spreading fast,and finger leathers the same.I eventually want some SPS but for now I just want to take advantage of 2 pcs of oregon that I can get cheap for the moment.

Any and all suggestions welcome,Thanks-Mark

[Peter Eichler]

Watts per gallon is a bunch of nonsense. It's all about the corals relation to the light source, reflectors, quality of the bulbs, etc. You should be fine with higher light loving SPS in your tank as far as lighting goes as long as you keep them in closer proximity to the metal halides. Also, keep in mind that a tank dominated by soft corals could end up making it tough to keep SPS corals because of the toxins they release.

[devgru]

Thanks Peter for your reply.Im not an expert on reef tanks so I seem to question everything.I too have been freshwater since I could walk,up until 5yrs ago I was even at the point of breeding oscars here locally.When I met my soon to be wife at that time I had 12 10gal 8 75g tanks and 2 125g all FULL of oscars and fry.She liked my display tank but wanted a saltwater as well.After debating for several months I made the plunge and havent looked back since.I haved learned alot from either trial and error or from the knowledgable people here at RC and my favorite LFS here in Orlando--Oceans Blue.I have been doing this slowly,not jumping into things too fast,but I'm really wanting to have a reef system with diversity.LPS,SPS,softies(?) bivalves,cryptic areas,the works.Thanks to a wealth of DIY info I have saved money and had the pleasures of making alot of equipment myself.

once again,thanks Peter

[Albanets202]

MH give a strong light, but narrow beam. PCs cover entire tank, but you have only 130W. I would definitely add another 175W MH. And watch for heating. If you need only one SPS, just place it under MH, in close proximity.

[IslandCrow]

I agree that watts per gallon is not a very useful tool, but watts per specimen wouldn't be of much use either. It's not like the coral takes what light it needs and then spreads it around to the other inhabitants. It's all about the PAR (Photosynthetic Active Radiation, or quanta of light the coral can use for photosynthesis) that reaches the coral. In other words, if I put a 175W MH on one side of the tank with a coral directly beneath it, and another on the other side, the coral is only getting the benefit of 175W of MH, not 350. That's just one of the reasons you're correct in that watts per gallon is not real useful. With fluorescent lighting, it's potentially more useful, since the bulbs generally span the entire length of the tank. All fluorescent lighting is not equal, though, so again the rule is not very useful.

OK, all that said, I've never been very impressed with 175W metal halides. I think they're great for small tanks with some of the less light demanding stony corals, but for the more light demanding SPS, I'd do a minimum of 2x250W MH, preferrably 2x400W. T-5 is also an option, but they don't have quite the penetration power of metal halide once the tank gets deeper than about 18".

[seapug]

With a tank that size with one 175W MH lamp, you will need to keep most SPS within about 12" of the light. Upgrading the fixture to a nice 2 X 250W setup with some actinic supplementation would open up your options a lot-- a very worthwhile investment for that tank.

[devgru]

thanks guys for your help.Im picking up a dual 400w PFO ballast monday(for only $30!).so IM moving the 175w to a 40g Breeder on the other side of the wall but on main sump.Ill pickup a spider reflector and bulb monday but will have to wait a little bit on the second refl/bulb.

Next question.My canopy,I built myself and there are 2 1x3's as cross beams at 2' and 4' from left side.where should I mount the 400's?on the 1st 2' and the last 2'?close together in the center?

I do have another 175w w/pendant that I could mount in center 2'?