Lighting

[Ozzie]

I am setting up a 55 gallon and I have a 4x55 Jalli PC fixture. Can anybody help as to what bulbs(50/50, o3 actinic,ultra actinic,10k etc..) to use and what can I keep with them. Is there a guide available on the web. Just getting started and want to have all my ducks in line before the water goes into the tank. THANKS

 

[Ozzie]

Any Links?

 

[Entacmaea]

Hi, and Welcome to REEFS! Your PC fixture is pretty bright for a 55gallon, and you should be able to keep most anything, though higher light anemones and SPS corals might prove challenging. Higher watt MH is really the way to go for those sun lovers! I do know people who are running quad PC's with great success though. The first consideration is deciding what you would like to keep in the tank.

As for bulbs, that is really an aesthetic choice. I would advise going to see some reefs tanks (friends, LFS, etc.) with different mixes and see what you like. A good rule of thumb is two 10k and two actinic. But some people consider this too blue, up to you.

Hope this helps!

 

[Ozzie]

Thanks for the response!!Is the watt per gallon rule an acurate way to measure lighting.? Just doesn't seem logicalo to me based on Spectrum, tank depth ,refraction,etc...

 

[mkirda]

Thanks for the response!!Is the watt per gallon rule an acurate way to measure lighting.? Just doesn't seem logicalo to me based on Spectrum, tank depth ,refraction,etc...

Watts per gallon is only accurate to a small degree... One problem is that it is not really comparable between lamp types... VHOs, CFs, and MHs all have different efficiencies. Even between bulbs in the same type (i.e. MHs), the efficiencies are not that comparable.

At any rate, based on measurements I have taken on CFs, the light intensity generated is not that great. Figure that the bottom of the tank will be the same level of light a reef at a depth of 100 feet would see at noon on a cloudless day in clear oceanic waters. The top of the tank might be 60 feet depth equivalent.

For what it's worth, the brightest tank I've measured was the equivalent of 25-45 feet...

Regards.
Mike Kirda

 

[Texas2Turkey]

Mike-

If you don't mind me asking -- what type of lighting and at tank depth did you get the best reading from?


Thanks,

 

[mkirda]

Mike-

If you don't mind me asking -- what type of lighting and at tank depth did you get the best reading from?

Well, "best" is highly subjective...

The highest light levels were from a system in Madison, WI.
It was a 120 gallon system lit with 2 400W Ushio bulbs, and 3 110W VHOs.
The upper third of this tank would be similar to light levels at 25 foot, and the bottom third was more like 45 feet. Most of the corals we like to keep occur over this range...

I'm still working on writing up the results and will get them published soon.
Regards.
Mike Kirda