25W, 2800K or 18W 6500K?

[m3th0d]

I have an 18T tank that I want to start planting this week but I don't know what lighting to get. I have an incandescent hood and I have two choices for lighting (screw-ins). One is 25W Philips Marathon 2800K and the other is a generic brand from Home Depot which is 19W and 6500K. Which one is better? The Marathon bulbs are stronger but have a crappy spectrum compared to the other brand's. Does the spectrum matter more than the number of watts?

The most demanding plants I plan on planting are:

Rotala indica
Ludwiga repens

[phanmc]

Wattage is more important, there has been some research done on the color temperature's affect on plants and animals but it's benefits isn't conclusive.

What higher color temperature does do is provide you with crisper light. the "soft white" temperature of 2700k is yellowish and washes out the color and definition compared to higher color temperature bulbs.

[MyShrimpDied]

Yeah, wattage is more important, but the look of a 25 watt 2700k bulb isnt pleasing. I have 2 on my 20 gallon and i really dont like the look of it, especially when my water is slightly cloudy *uggh*

I recently bought 2 28watt 5000k bulbs, those will be much better and much more white....hopefully.

but again, a good rule to follow is: Go with whats good for your tank, not what looks best.

BTW - Where did you find screw in base 6500k bulbs? i searched lots a places but the highest screw in base bulb in terms of kelvin were 5000 and 5100

~ MyShrimpDied

[djlen]

Myshrimp -
Check this link for bulbs:
http://www.1000bulbs.com/

Len

[MyShrimpDied]

Awwww crud, i always hate when i order stuff and then i find something better, makes a person feel like a complete moron, hopefully the other bulbs with by as white as i hope they'll be.

~ MyShrimpDied

[m3th0d]

I heard plants only take what's in the 3,600K-8,500K range?

I might just return these Marathon bulbs.. I'm really not liking the idea it's only 2,800K.

djlen - I don't see any 6,500K screw-in compacts at that website..

[MyShrimpDied]

wait...isnt that what you want? not to be nosy or anything :)

~ MyShrimpDied

[Torf]

I believe it is Servicelighting.com or somthing like that where you can order 14w 6500K bulbs. They also have some 42w 6500k bulbs as well if they fit in your hood.

They won't fit in mine, so I use 8 of the little 14w bulbs.

Found Links:

http://www.servicelighting.com/catalog_product.cfm?first_visit=no&source=General&prod=TC01465

http://www.servicelighting.com/catalog_product.cfm?first_visit=no&source=General&prod=TC28946

I am quite happy so far with my 8 little 14w bulbs. They start instantly, and don't have that annoying delay that other CF bulbs have. Someday, I'll make a total custom hood that had room for the 42's.

[karfixer]

Originally posted by m3th0d
I heard plants only take what's in the 3,600K-8,500K range?

I might just return these Marathon bulbs.. I'm really not liking the idea it's only 2,800K.

djlen - I don't see any 6,500K screw-in compacts at that website.. Go to the screw-in flourecents, they start carrying 6500K bulbs @ 27W size, I use the 42W over several of my tanks-but not exclusivly. They have 5100K bulbs down to 4W, and the 5100's that I have used look much better than the "soft white" 2700's that are commonly avalible. Steve