Lighting for 25" Deep Macro Tank?

[Dave Legacy]

Hi,

I have a question about lighting my 37G Tall tank, which I plan to keep only macro in. I have a Coralife 2x65W light fixture will be using two 6,700K power compact fluorescents instead of the daylight/actinic setup it comes with. My concern is that the tank is 25" deep, and that's a long way for PCF lighting to penetrate.

Will this be suffiecient for growing macroalgaes? Maybe only certain kinds?

Thanks,
David

 

[graveyardworm]

I think you'll be fine keeping most macros under that light. It is a little on the low side, but most macros are adaptable as long as nutrients are available. I think the worst that may happen is slow growth.

 

[Dave Legacy]

Maybe I'll try to start them at the surface and work them down until I reach the limit. What would be a more recommended lighting setup for this deep of a tank?

 

[mr. bojangsjang]

t-5 would be a good option.

 

[BruceW]

I have an Orbit fixture with 2 x 65 on my 37 tall and the macros do just fine. I just used the bulbs it came with as I also have some shrooms and everything is doing ok so far. It has had this fixture on it for about 6 months. Before that I had a single 65 watt 50/50 and I was growing tons of polifera. After you figure in the sand and rocks your tank isn't really that deep.

Bruce

 

[piercho]

Dave, are you asking what fixture could give you higher illumination levels at a reasonable wattage? 150W 6500K and 10,000K MH bulbs in a good fixture will produce higher PAR levels than you can get with a distributed source like PC, T5, or VHO. This Sunlight Supply Lumen Max 3 is an efficient, fairly small fixture. The Icecap Spot Fixture uses EYE (Iwasaki) PAR 36 flood bulbs and is also fairly small.

As far as MH lamps, I think an optimum plant lamp is still the EYE 6500K, which is available at 150W in SE, DE, and PAR 36. It's a decent analog to real sunlight with higher efficiency than most MH.

But T5 and PCare also good light choices, with the better net efficiency from T5 because its easier to reflect light from T5 into the tank. For your tank, unless you need to generate high PAR at the sandbed to grow some particular plant, I would stick with PC or T5, myself.

 

[pjf]

Light Intensity and Depth

Light Intensity and Depth

Stick with your 2 x 65-watt PC fixture. A standard 37-gallon aquarium is 30” long and 30” light fixtures are hard to find. If your fixture mounts to the tank, that is even better because more of the light will be directed into your aquarium.

Unless your plants provide too much shade, don’t be too concerned about the depth. Light intensity measured at a 25” depth does not differ much from light intensity measured closer to the surface. Here’s a link to a post about this subject:

http://fins.actwin.com/aquatic-plants/month.9510/msg00297.html