Bulb Color Combination

[daveverdo]

Hi Everyone,

I am putting together a hood for a 30g (12x36x18) FOWLR tank. The planned project will have 3 39W T5HO bulbs. Two bulbs are on one circuit and the third is a single. Although this may be overkill for FORWL I figured I'd do it now rather than having to move things around to fit more in later. I also am adding 2 AC fans each moving about 13CFM. I was also thinking of adding some lunar light.

Now the questions:

What is a good combination of 3 bulbs for this setup? I can set a timer to have one, two or three bulbs on a time. Is there a bulb that I can put in the single to use as a lunar or will any 39W HO be to bright for that?

If I don't use the single as a lunar what would be a good sequence to turn on the lights?

Thanks,
Dave

[Ninong]

Hi Everyone,

Hi Dave!

What is a good combination of 3 bulbs for this setup?

I would go with one actinic and two comparable to 10,000K. If you were going with VHO that would be one SuperActinic and two ActinicWhite. Different manufacturers have different names. In any case, I would go with one lamp that is strictly blue (usually called actinic) and two that are white, usually referred to as 10,000K or maybe 12,000K. I wouldn't get anything in the daylight range (6500K). I'm not sure what they call the various T5's but if you tell me what their claimed Kelvin ratings are, that will tell us all we need to know.

Is there a bulb that I can put in the single to use as a lunar or will any 39W HO be to bright for that?

No! That won't work for a "lunar light." If you are determined to put a small nightlight ("lunar" light) over a FOWLR tank, get a tiny LED type light. No need to keep the fish up all night.

Lunar lights are usually reserved for reef aquaria with corals, clams, etc., but you could stick one over a FOWLR tank if you want. A true lunar light would be dimmable and it would be controlled to match lunar rise and set times and lunar phase intensity. This can be done with expensive controllers and incandescent lamps. Anything less is just a night light.

The moon is not out every night and it is not out at the same times. A true moonlight would come on whenever the moon is "out," even if it's daytime. And the intensity would be a match for lunar intensity based on the particular phase of the moon. That can only be done with controllers.

If I don't use the single as a lunar what would be a good sequence to turn on the lights?

Assuming 12 hrs/day total light (to match equatorial night/day), bring the actinic on first, then another lamp one hour later and the third lamp one hour after that (assuming you can control all three separately). The first lamp would stay on for 12 hrs, the second lamp would stay on for 10 hrs and the third lamp would stay on for 8 hrs.

Since it's a FOWLR tank, you can adjust the Kelvin mix of the three lamps to suit your personal preferences. The fish really don't care all that much.

[Reefland]

Hi daveverdo,