12000K lighting ok for reef?

[justin100]

I need to know if a 2- 260 watt lighting system with 2- 12000K bulbs and 2- actinic 03 bulbs are ok to start a 100 gallon reef tank?

[jlam]

Well the question is really what are you hoping to keep? If you are doing soft and some LPS then yes. If you are going to keep SPS then might not be enought light.

Jason

[brewercm]

A good rule of thumb is 1 light for every 2 feet of tank length.
250 watt up to 24 inch water depth, over that go with 400 watt.

This is just a genral guideline, the 12k MH and actinic should look nice though.

[GaryP]

Here's another rule of thumb.

>100 watts per square foot for an SPS tank. The other issue is depth. You need higher wattage bulbs (400 watts) for tanks over 24" deep.

[justin100]

This system would have 520 watts is that ok on a 100 gallon?
Thank you the help!

[Tim Marvin]

Again, like Jlam posted, it depends on what you are going to keep. It should be fine for all softies and LPS. SPS and clams usually do best under halides.

[GaryP]

If your 100 gal. is 72 X 18" that would make it 9 sq. ft.

520 watts/ 9 sq. ft. = 57.8 watts/sq. ft.

That would be ok for low to modetrate light corals but you would have a problem with SPS, most clams, and most anemones, and a few soft corals & LPS. As with everything else, you need to decide what kind of critters you want in the tank then determine what equipment is necessary. To many people do it the other way around.

To give you a comparison, I am running 73 watts per sq. ft. in a very successful softie/LPS tank. I feel comfortable putting anything in it except for SPS and maxima or crocea clams.

[Bucky-Katt]

This is a very interesting discussion. I have never heard of calculating light requirements like this. What watts/sqft would you recommend to keep a clam (maxima or crocea)

Thank you so much. Hope you don't mind me piggy-backing my question onto yours justin.

Brian

[GaryP]

This is a very interesting discussion. I have never heard of calculating light requirements like this. What watts/sqft would you recommend to keep a clam (maxima or crocea)Brian

The light requirements are about the same as SPS, >100 watt/sq. ft.

However, remember what was said earlier... tank depth can make a big difference. Watts/Sq. Ft. is certainly a better rule of thumb than watts/gal. which is what you more commonly see. The amount of light is also going to depend on the depth at which you put the clam. I prefer putting them on the sand bed but some folks like having then up higher in the LR.

My clams have been doing very well for several years in my SPS tank down on the bottom in a 21" deep tank with 91 watts/gal. There's about a 3-4 inch sand bed so their mantle is probably about 14-15 inches from the surface.

[Bucky-Katt]

Thanks for the info, Gary!

Brian

[GaryP]

That's why we are here. Glad to help. There is some very good info out there on the net. It might be worth your time to do a little research.

[OldSalty]

Gary, You have 91 watts per gallon on your tank :w00t or is that a typo?

[GaryP]

Yeppers. Definitely a typo. Actually more like brain flatulence.

What I meant was 91 watts per sq. ft.

[Ram_Puppy]

Brian, you thread hijacker. :)

another thing to take into consideration with a deep tank (over 24") is how deep your sand bed is... and where you will be growing most of your high light SPS in the tank. For instance My current tank plan for my 30" cube, is to primarily light it with 2 x 250 watt HM, 1 20K, 1 10K. Will I penetrate all 30 inches of water enough to grow SPS at the bottom? No, do I care? No. I don't want to grow SPS or Clams on the bottom of my tank. In addition, there will be at least 4 inches of sand (were now at 26"s of depth with that) add to the fact that most coral (note I did not say all) grows on solid rock, and you can pretty much gurantee even the low spots in my rock work will be around 2 inches in height, or, the zoo and shroom rocks I buy will be, and I arrive at that magical depth of 24 or less inches. (this does not take into account the T-5's going over the tank as well)

Regardless, that last couple inches will be a nice area for softies. It comes down to, as Jason and Tim said, what you want to keep, but also, WHERE you want to keep it in the tank.

[Richard]

Here's another general rule of thumb that goes by light instead of watts....

1,500 to 2,500 Lumens/sq. ft for low light corals
4,000 to 5,000 for medium light corals
7,00 to 8,000 Lumens/ sq. ft. for high light corals

A general guide to figure out lumens...
50 Lumen/watt - NO Fluorescent
56 Lumen/watt – VHO Fluorescent
85 Lumen/watt – CFL Fluorescent
75 Lumen/watt – Metal Halide
85 Lumen/watt – HQI Metal Halide

[AlienAnchovies]

what do you guys think about 260 watts of pc lighting on a 29 gallon
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=4316117607&ssPage Name=STRK:MEWN:IT

i went ahead and bought that last week
im wondering how many watts per gallon that'll put me at and what i cant keep under that

[GaryP]

You should be able to put anything you want to under those lights. Some of the soft corals like mushrooms might not like that much light, especially the blue and purple discosoma.

[garagebrian]

For the 260 watts of PC lighting above, and really, for any lighting calculation, you need to know which type of bulbs are being used right? If AA bought 2 blue lights then the effective watts would be 130 of white light right? I'm assuming that actinic/blue lights are not figured in the calculation at all.

B.

[AlienAnchovies]

before the new lights i had
1 55 watt 10k daylight and 1 55 actinic

now i have
2 10k daylight and 2 actinic o3 bulbs
grand total wattage of both lights = 260