Question on lighting - Tropical Fish Keeping - Aquarium fish care and resources
LinkBack Thread Tools
post #1 of 6 Old 02-26-2012, 09:14 AM Thread Starter
Question on lighting

i have a 55 gallon and just replaced the 32w 48' 8000k full spectrum daylight t8 bulb with an plant and aquarium f40 t12 40w wide spectrum. It says it's designed specially for plant growth. my plants had been growing very slowly. Is this light i got any better? It doesnt look nearly as bright. I also had been leaving lights on only 8 hrs a day and read that 10 may be better if you have live plants. If this light isnt any better what type of light would be recommended? Also it says light output is 1900 lumens

Last edited by smit3183; 02-26-2012 at 09:17 AM.
smit3183 is offline  
Sponsored Links
post #2 of 6 Old 02-26-2012, 09:33 AM
beetlebz's Avatar
welp, Im not sure it was such a necessary upgrade to be honest. The original T8 might have been outside the traditional color spectrum, as most recommend 5500-7000k, but I dont think it was that big of a deal. The 30 watt T8 is actually going to be a little bit brighter than a 40 watt T12. T12 bulbs are not as efficient as T8s. I have 5000k bulbs on my planted tanks right up through 8000k bulbs. The 5000k definitely grow better, but the 8000k are no slouch.

Dedicated, converted, lowes / home depot bulb buyer!
beetlebz is offline  
post #3 of 6 Old 02-26-2012, 09:55 AM
Quantum's Avatar
The issue with lighting is twofold: the amount and the type. As mentioned, the T12 is less effiecient than the T8, so you haven't increased light output even though it is higher watts (though I would argue light output is about the same and the dimmer appearance and low lumen number is due to the different spectral output and not intensity). You have changed the light qualitatively, as the 'plant' bulb will likely emit more blue and red wavelength light (likely has a pinkish hue).

Having said that, you should be able to get good plant growth with either bulb. If not, my guess is something else is going on. How old was the T8 bulb? What do you use for filtration? Use fertilizer? What plants are you trying to grow?

Last edited by Quantum; 02-26-2012 at 09:58 AM. Reason: spelling
Quantum is offline  
post #4 of 6 Old 02-26-2012, 01:06 PM
Byron's Avatar
The so-called "plant" and "aquarium" tubes are less intense, plus there is the hue issue because they distort plant and fish colours. I would simply go to a hardware store like Home Depot or Lowe's and get a 6500K 48-inch T8 tube. GE, Phillips and Sylvannia make them, just get the one with 6500K and you're set. I use these, they work very well. And they are less expensive, here in Canada a package of 2 sells for $7.

From my experience with the type of tube you now have, long-term, the plants will not respond as well. The intensity is less, however we measure it.


Byron Hosking, BMus, MA
Vancouver, BC, Canada

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian. [unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If youíre going to take it under your wing then youíre responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]
Byron is offline  
post #5 of 6 Old 02-26-2012, 06:40 PM
beetlebz's Avatar
Oh, not to mention running T12s on T8 ballasts and vice versa can cause problems with the ballast long term, in some cases. Just an FYI.

x2 on just getting a daylight bulb from the hardware store. Every one of them is likely to carry them, and they is cheap.

Dedicated, converted, lowes / home depot bulb buyer!
beetlebz is offline  
post #6 of 6 Old 02-27-2012, 03:19 AM
MinaMinaMina's Avatar
Also, with running a T12 lamp on a T8 fixture... since the T12 has a larger diameter and therefore sits closer to the fixture, sometimes the proximity can produce enough heat to warp the housing and/or plastic reflector. Its happened.

"My dither fish need dither fish!"
MinaMinaMina is offline  

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
Question about lighting TED45 Beginner Freshwater Aquarium 3 01-11-2011 06:23 PM
Lighting Question!! volzb1 Beginner Freshwater Aquarium 1 06-29-2008 11:11 AM
Lighting Question Puffer Saltwater Aquarium Equipment 4 03-19-2008 12:08 PM
a lighting question and a tank question beetlebz Freshwater Aquarium Equipment 2 12-12-2007 10:14 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome