Is a power compact 2x36watt fixture too much light for a 12G tank?

[tastingSalty]

what do you guys think?

[tastingSalty]

dimensions of the tank are 21x16x10

[tastingSalty]

bump

[kgross]

What are you planning on keeping in the tank?

The standard 12 gallon nanocube DX has 2 24 watt PCs, and in mine have a couple of sps corals, a clam and lots of softies without any problems. Your 2 x36 is not a lot more.

Kim

[TammyLiz]

No, not too much. I'm in the same boat as Kim with the NC DX and I wish there was more light. I'm shocked at how fast the PC bulbs get old, though. After six months algae goes nuts and not long after that even zoas start stretching for more light. Go with T5 or MH if you can, IMO.

[freddy4130]

i have 96 watts of PC over my ten gallon.

[walkthedog]

It's not going to be too much. You can't use the watts/gallon thing; it don't work like that. Depth of the tank and the intensity of the light.

Watts per gallon (w/g) is not a very good method of determining light requirements. Following this "rule of thumb", 100 watts over a five-gallon tank (20w/g) appears much better than that same 100 watts over a ten-gallon tank (10w/g), but the intensity is lacking in both cases. One hundred watts is still one hundred watts, no matter how you slice it. Intensity is the key, the more the better. To paraphrase a recent post by Eric Borneman, “if a coral, for example, requires 15,000 lux to saturate, it needs to get that amount of light regardless of tank size. So, if a 175 watt metal halide puts out 17,500 lux at the water surface and 8,000 lux ten inches down, it’s enough light for the coral at the surface but not at the bottom.”

[Scythanith]

Not too much light in my opinion. I'm running two overdriven T5's with individual reflectors on an IC 660 on a standard 10 gallon. I don't have any scientific measurements but I know it keeps all sorts of corals happy for me. Just keep some airflow on the bulbs and endcaps to increase to longevitiy of the bulbs.

[tastingSalty]

Thanks for the info, especially walkthedog. So the common consensus is to err on the side of too much (regarding the 'rule of thumb')? Is there any way to calculate 'lux'?

[tastingSalty]

I hope to eventually have some SPS corals in there

[tastingSalty]

It is possible to have too much lighting and burn the corals, right?

[kgross]

Yes it is. But normally it is more that you burn them by an increase in lighting, not that there is just to much.

Kim

[tastingSalty]

oh ok . . that explains a lot, then. i thought that it was usually from having too much. thanks.

[kgross]

Think of you and sun burns. First nice day of the year, lots of people get sun burns. Last days of summer very few people (in comparison) get sun burns.

Kim