Mixing Kelvins...

[Sicklid]

I would like to add another bulb over my 2.5 nano plant tank. I am currently using a 13w CF 5000k lamp, and am not happy with how the light reaches the back corners, mainly not penetrating deep enough to the lower leaves of my stem plants. I am adding another lamp, but would be switching to 9w lamps for both, giving me 18w total instead of the 13w I have now, just more spread out... The one thing I am considering is running one @ 6,700K and the other @ 2,700K, sort of experimentally to broaden the spectrum a bit. Any reason this would be bad, i.e. algae more opportunistic at this spectrum?

I know everyone is gonna say that 5,000k to 6,700k is where you want to be, but I have a sneaky suspicion that is not totally necessary, as I have friends who grow plants under incandescent bulbs which appear very warm. I know that 2,700k will just make things appear more red/orange, but that is what I am after, since I am not crazy about the starker white/blue spectrum from the 6,700k bulbs. Combined with a 6,700k it should average out a bit, no? The problem I would have is where to place which lamp, one more towards the front or back on center, or spread them out left and right a bit... I feel the 6,700k at the back with the warmer bulb up front will do me just fine, but I may still have the problem of the light being in the middle and not in the corners. My canopy is painted white inside. If I put one toward the left and one towards the right, I am worried one side will benefit or lack something the other won't have, and vice versa. I mean this is only a 2.5g though, so maybe it will not even be an issue. Any thoughts?

My goal here is more overall light, and not so much white/blue, but slightly warmer... Will this do what I want? Anyone running a setup like this?

 

[rkilling1]

I am running 9325K and 4100K on my 28 gallon, but the 4100K is too yellow for my tastes.

2700K my be just fine for growing plants, but you would have to look at the spectrum of the light and not just the temp. to know if it will be good or not. ie having the spectrum peaks in the blue and red areas.

 

[Sicklid]

Where would that be indicated? I mean, I don't think it shows that on the lamps package and I have no meters for testing it myself.

 

[SparKy697]

See if you can find information on the manufacturers site. Where did you buy the lamps? you may find some help there too.

 

[Sicklid]

Haven't bought them yet, it is just that all I can find in that lamp base at that wattage is 2,700K, unless I spend much more than that for a 6,700k lamp from hellolights.com.

 

[rkilling1]

Do you have a link to the bulb in question?

 

[Sicklid]

Scratch it... I think I've decided on a 13w 6,700k and a 13w 5,000k... only now with co2 injection

 

[hashbaz]

Perhaps my suggestion is too late - but I really like the idea of being able to mix and match (with two 9w bulbs) and experiment to see what looks good and balance this with how the plants/algae respond. It's also more monetarily feasible with the smaller bulbs.

 

[Sicklid]

Yes, but my ballast is a gx23 base, and the only 9 watt bulbs I can find locally are g23 base bulbs... They won't work. But I am going to do the two 13 watt bulbs. I finally decided on a 6,700k and a 3,000k or something like that, available locally from a lighting store. It is only for a 2.5 gal. tank, so I can do DIY c02 for cheap, and probably be okay with that and Flourish Excel added...