T5 Light Penetration & Sufficient Wattage

[mossyoaktoe]

Hey everybody I've searched around a bit for a good solid answer as to how deep T5 lighting effectively penetrates water, assuming that the reflectors are of average quality.

The reason I ask is because I am unsure if I am providing enough light to the corals at the bottom of my tank as well as those those sit centered and receive light through the middle glass support atop the tank (which I'm sure soaks up enough light on its own). Currently I have a 48", 6 bulb T5 HO 54w fixture with individual reflectors & quick-fit DIY moonlight. Current bulbs in order back to front are 2 blue actinic,1 11000k white, 1 blue actinic, 1 11000k white, 1 blue actinic. My light sits about 3.5 inches above the water and water to bed is 20". I suppose I may just need to replace another actinic with another daylight bulb, however I do prefer the "bluer" look to my tank.

I have an unknown anemone, open brain coral, frogspawn, toadstool leather, and another questionable leather all on the bottom of my tank. Upwards from there I stock a few zoa frags, green star polyp, acrophora (i think) and a few mushrooms; along with my fish stock.

This is my first tank of any type and I wanted to do it right and affordably, that's why I chose this fixture.

Any support and or feedback on T5 light penetration, my light sufficiency, and what other corals I could support with this setup will be greatly appreciated.

Thanks,
mossyoaktoe

 

[nanoreefing4fun]

Re: http://www.reefsanctuary.com/forums/images/rT5 Light Penetration & Sufficient Wat

to ReefSanctuary, a real Sanctuary of reef forums, with lots of very nice members

Pretty tank - sure some members will have some advise on the lights

 

[BigAl07]

Hello and welcome.

I'm going to start off with one of Glenn's favorite threads to link to (in terms of lighting anyway)
http://www.reefsanctuary.com/forums/equipment/50016-basics-lighting-reef-systems.html

That's a GREAT primer in Reef Lighting 101 and it's written in simple yet complete terms.


In my own personal opinion I think T5's are only really viable for HIGH LIGHT needing coral down to the 18" depth and only then with high quality components. If you were to Over-Drive them you may get decent penetration slightly deeper but every inch of water dramatically cuts down on light penetration. The amount isn't linear but exponential.

I LOVE T5's (read back some of my posts and you'll see I'm a big fan of T5's) but they do have some limitations (noted above). From 18"24" I'd only place low to medium light loving coral lower in the tank.

Here's how I "see light". . .

0"-18" T5's ROCK!
0" - 18" 150w MH work well
18" - 24" T5's are getting weak.
18" - 24" I like to see 250w MH
24"+ I like to see 400w MH especially if you have HIGH LIGHT demanding coral.

 

[mossyoaktoe]

Hey I appreciate your reply. Its funny to me now but right after I posted the ?'s I found and soaked up the "Basics of Lighting for Reef Systems" thread, really a perfectly clear, straight forward, quality post.

As far as my system goes its only 20" at the deepest from topwater to the top of my substrate so I think my corals should be just fine.

Do you think that building in fans can really improve penetration & intensity by 50% though? It seems like I shouldn't wait another second to retro fit them into my light if its that big of a deal..

 

[BigAl07]

T5 bulbs (and really most light emitting sources) benefit from active cooling. Fluorescent tubes (T5s are this) have a very narrow temp range where they are more efficient. I don't remember that number nor do I remember how much per degree but it's enough to say they very easily over-heat and lose significant efficiency. I don't know about 50% but it's enough to where I'm a fan of fans :LOL:

Also bulb life is shortened greatly by increased heat so by adding some active cooling you're getting DOUBLE benefits.

bulb cooling is a science in itself and I think if you dig around enough you'll find some in-depth reading about T5 cooling in fact to the point of which END of the bulb should be cooled the most. Apparently if you want to get picky about it you'll want to cool from a certain end of the tube! That's too much for my needs but you may like to research and attempt that route.

Happy Reefing

 

[ddinox64]

I run T5s on my 90g 20 inches deep and about 3" off of water. Growing everything in there.

 

[Alien2100]

I'd personally change out at least one of the actinics for another 11000K. If not two...

 

[cheely13]

I run a 6 bulb with individual reflectors on my 160 i penetrate 20 inches of water i have a 4 inch sand bed i did have a problem with a leather coral i think i had too high it was starting to bleach out moved it to the bottom and it growing good now. I do have a 400w MH on the far end for high light loving stuff just dont have any yet.