"Warmer" colors in T5 bulbs?

[geekboy]

I recently received shipment on a new 4 bulb 48" T5 fixture for my 75 gallon goldfish tank. It happens to be one of the Odyssea / Aquatrader units that have a dubious reputation, so I'll be keeping an eye on it to make sure it doesn't catch fire. It was a good price on eBay, and I have to say that it is impressive so far. The extra light produced is incredible.

My main reason for the purchase was to upgrade the respectable but underwhelming single-tube Perfecto standard flourescent tube I was running. I wanted more light, and I thought perhaps I could dabble in live plants down the road.

Now for my question, which is: what are my best options for a "warmer" less sterile-looking T5 Bulb? The Odyssea fixture came with bulbs that I imagine cover the widest range of customers. It has two "daylight" bulbs, and two actinic bulbs. For my goldfish, the actinic bulbs are way out of character. The daylight bulbs are pretty good, but I'd still like to find something that isn't so "cool white", perhaps with more of the red/yellow part of the spectrum.

Part of my problem might just be that I've been ruined by the generic grow-tube that the old fixture had. I'm sure I'll eventually get used to the new one, but any thoughts would be appreciated.

 

[SubRosa]

That's alot of light for dabbling with plants! You have enough light for all but the most demanding plants. You might consider running only half of it. I have 2x54w T5 over my 75 gal river tank and algae growth is pretty rapid. As far as bulb selection you want to look for bulbs with lower K value, in the range of 5500 to 8000. Bulbs designed specifically for plant growth generally have a pinkish glow which might give you the look you want.

 

[geekboy]

I agree that it's a bit overkill. I was originally looking at 2-bulb fixtures, but couldn't pass up the chance at a 4-bulb for a lower price. No sense wondering if I would have wanted a brighter fixture after the fact. It's as you say -- I can run just two of the bulbs if it's a problem. My 48 x 13 x 24" tank is decently deep anyhow.

Oddly, it looks like I might have trouble tracking down anything less than a 10,000K that will fit. I don't have a LFS per se, and my Canadian online shops of choice seem to focus on actinic and 10,000K daylight bulbs.

 

[SubRosa]

My local supplier equiptment supplier won't ship fluorescent tubes. Maybe try a garden center or a hydroponics supply house?

 

[SubRosa]

Try www.htgsupply.com

 

[geekboy]

Thanks for the link. I'm trying my best not to have to import them, but I'll keep that source in mind. At least I know now that the bulbs exist.

Edit: I guess I took for granted that I might find these bulbs at a simple hardware store. Looks like I can get 4100K Bulbs that might not look too bad, especially if I use them in combination with the 12000K daylight bulbs I already have.

 

[zzyzx85]

for plants, look for bulbs between 6500K to 10000K, which range from "warm" daylight to "true" daylight. the lower the number, the more yellow and "warm" the light color is. 10000K is pretty much true white.

the 12000K bulbs you have are probably on the blue-ish side, right?

 

[geekboy]

Yeah, the 12000K has a slightly oceanic quality to it. Here's a pic that can be easily compared to the daylight from the window in the background.

 

[geekboy]

For those interested, I was able to special order some 48" T5 bulbs from my local hardware store (Home Hardware) for $11.99 CDN each. They are by Osram/Sylvania, and rated at 4100K at 54W. The following comparison shots are taken against natural light from the window in the background. I attempted to match the background color and brightness for a fair comparison.

The provided "Oddysea" freebie 12000K bulbs on their own:

The 4100K bulbs (which replaced the actinic):

To my eye, the 12000K is too blue, and the 4100K is too yellow. Put them together however, and they nearly match the daylight coming through the window. I couldn't be more happy.

Now the only other concern I have is that this fixture does run on the hot side when all four bulbs are lit. I'll probably be running it at half-power most of the time during the summer, just so I don't temp fate, or heat up the tank/room too much.