I'm looking to replace my single T5HO bulb on my 30L low-tech/el natural aquarium with something more pleasing to the eye, so wanted to ask what specific bulbs folks have used and are happy with, both in terms of both appearance and plant growth.
I realize there is alot of info on here about color temp and and photosynthetic pigments etc (which i mostly understand, so no need to repeat that here) but few recommendations about available T5HO bulb models - please point out any threads if i've missed them. I agree that looking at the K-rating can be very misleading, and often find the spectral charts, if provided, unrepresentative or at best not very useful for really knowing how its going to look.
I have only a single bulb on the tank (i do not want to dose ferts or CO2), a 39W Giesemann powerchrome midday/6000k bulb, which has worked well in terms of plant growth - excellent growth and very little algae. But, it gives a fairly green cast to the tank. Particularly noticeable is that the driftwood and reddish/orangish rocks in the tank do not look very good. The colors on the fish are ok, but not great. (possibly, it simply needs to be replaced after 6 months, as I do not recall being so bothered by the color cast when i first set it up...but my impression was these lamps would last longer?)
I recently bought two additional bulbs to try them out:
1. Current USA Slimpaq 6700k T5HO 39w daylight bulb: substantially more green than the giesemann. i really cant stand it, so that was a total waste of money (mail-order, too much bother to box it up and ship it back).
2. Aquamedic Aqualine Planta / "Plant Grow" 39w. No k-rating, but appears fairly pinkish, like many plant bulbs. I dont mind the pink color cast - fish, wood, rocks all look better - but it is substantially dimmer than the Giesemann (or the Current USA). I assume thats because it has relatively little green in the output spectrum.
I was considering buying a few other bulbs to see if the ideal thing is out there, but thought before i probably waste more money, I'd ask around to see if folks have any specific recommendations for what they've used and liked, or used and not liked, in the T5HO realm. Some possibilities:
1. Hagen Powerglow 18000k bulb, saw this at a local petsmart, so at least would be easy to return. 18k kinda scares me, although from what ive read (and experienced) k-rating is often poorly correlated to how the bulb will actually appear and function for growth.
They also have a "Life-glow" bulb, although i was scared by its 6700 k-rating (which obviously i should ignore and probably just buy these two, try them out, and return if necessary).
2. Gieseman powerchrome aquaflora: seems like perhaps the best bet as the giesemann appear to be generally well-regarded. But perhaps it will be like the aquamedic planta - good colorwise, but overall too dim for viewing.
3. UV Lighting Aquasun:
I fear that the best or perhaps only way to get what I want - good colors + sufficient viewing brightness - may be to run two bulbs (say a plant and a 6000k or so bulb), but I think that would be more light than I'm willing to deal with in terms of having to then dose ferts or CO2.
On a previous tank with CF lights I quite liked the GE 9250k lamps - bright plus good colors -but that does not appear to be available in T5HO format.
Thanks in advance for any specific suggestions or recommendations.