24" depth, who runs t5, who runs MH?

[gobytron]

I have recently bought a bunch of used systems in order to economically and expeditiously establish my 90 gallon tank.

I currently have 2 250W Phoenix 14k running over this tank and I have no complaints, however, I find the diversity in t5 bulbs intriguing and since my tank is host to many sps and a few clams; I thought I would query this great forum for peoples experience with a tank of this depth and t5 vs mh for sps, clams and other high light loving organisms...

Do you really get the same penetration and par with something like a 6 bulb tek fixture (this is the fixture I would try to find if I did switch to t5) or something comparable?

I know there is more to it than optics, but to me, I just can't see how something as bright as a mh bulb could compare to even 6 bulbs of something that is nowhere near as bright to the naked eye...


Thoughts?

links to this same question being asked by other curious newbs?

Pictures?

all appreciated, thank you.

[Myka]

Originally Posted by gobytron

Do you really get the same penetration and par with something like a 6 bulb tek fixture (this is the fixture I would try to find if I did switch to t5) or something comparable?

To answer the question very simply...ABSOLUTELY NOT.

This question has been debated to death. You will have the T5 diehards, and the MH diehards who will have differing opinions, and usually strong opinions at that. I used to be a diehard MH, then I switched to T5 and thought that was the cat's @$$, now I'm back to MH.

Depth penetration is a fairly straight forward answer even though you will get differing opinons which is kinda silly if you ask me, as there are numerous "case studies" that show T5 does not even come close to the depth penetration of MH when compared fairly.

Now, when people are comparing MH to T5 for PAR they USUALLY don't compare fairly as it is difficult to do. First, you need 8x54w T5s to fairly compare to 2x[any watt] MH lamps or 4x54w to a single MH lamp. Otherwise you are not getting the same coverage of sq ft of usable light. Next, you have to compare the same Kelvin. You can't compare 10000K to 14000K and say that you have compared fairly because the higher Kelvin puts out less PAR in comparison to the same bulb in a lower Kelvin. Then you have issues like reflector quality. And the biggest variable?? What bulb/ballast combination? If you pick a poor bulb/ballast combination you may get 1/4 of the PAR out of that setup as you would if you ran a different bulb/ballast combination of the same wattage. You can also get more PAR out of a lower watt than a higher watt just by choosing different bulbs/ballasts.

SO...if you want to compare fairly, or you want a more accurate answer you need to ask something more like this:

Will I get higher PAR from 2x250w electronic ballasts with Giesemann 13,000K DE bulbs and LumenMax 3 reflectors or a 8x54w Tek T5 running 3 Fiji Purples and 5 AquaScience 15,000K??

The answer to that would be that you would get higher PAR from the MH set up in this particular case. I'm going to take an educated guess and say you will get about 25-30% more PAR out of the MH at 24" depth. Although the PAR at the water's surface would probably be within 10-15% of eachother, with the MH still leading.

Another issue with lighting that many many people fail to consider is water clarity. There are many reasons for higher or lower water clarity, and generally people with less experience are less likely to have high water clarity. This HUGELY affects the amount of light penetration, and is not as easy to achieve as you may think. I'm not going to go into that any more though because that's a fairly large topic as well.

Originally Posted by gobytron

I thought I would query this great forum for peoples experience with a tank of this depth and t5 vs mh for sps, clams and other high light loving organisms...

Imo, there is no comparison in your case with the combination of significant depth (24") and the critters you are keeping. MH would be the ONLY option if I was in your place. Oh, and I am!! I am setting up a 24" deep tank, and am using 2x250w MH with supplemental T5 blues/actinics. I absolutely would not consider T5s for my tank, and I only keep LPS, a lower light clam, and a lower light anemone. Although I do plan to add a few SPS to the tank.

[tang daddy]

Good answer ^

And now from my own experience if you have a tank with low depth like say 18 inches a t5 54w fixture may grow sps however for a deeper depth it will keep stuff alive but not thrive!

I had a 6 bulb tek over my 120g with 2 extra single t5's full sps tank and in 3 months went back to 2x250w hqi. While some sps did well with t5 at the 8in and up mark the rest coloured down, so IMO mh hqi with sps FTW!!!!!

[gobytron]

Thanks for the diatribe, I appreciate your comments.

I'm amazed so much info can be received from someone who has a 33 gallon sumpless and skimmerless tank.


I would love to see your set up Myka, do you have any pics?

I have so many pieces of equipment that it's confusing and I was wondering if it were all necessary plus, I am looking to spend 400-500 on an new skimmer that I was under the impression was mandatory. I'd be sincerely interested to know about your maintenance schedule and if you have any problems with algae or organic waste build up etc...

I wonder what difference the usable light makes if my tank is only 18" wide?
wouldn't a 6 bulb fixture give me all the usable light I need where as a MH light might be spilling over the sides as i have read a MH bulb should cover about 2 square feet and thats about 6" too big?

I would love to see a comparison of the best and most advanced MH technology against the best and most advanced T5, regardless of differences in reflectors, ballasts and such, just a bare knuckles brawl between these two top offerings of these mainstays in this hobby.

Also, some links to those case studies you mentioned that set the record straight on t5 vs MH depth penetration would be really helpful, can you post the links to them please?

I apologize for not offering enough specifics on what mh I wanted to compare to what t5s for you to answer my query, I guess i was just hoping for some general info on the two and their individual benefits versus short comings, but maybe thats impossible, I am just a newbie

if anyone can even add anything after that, I'd still love to hear some discussion...

[gobytron]

Originally Posted by tang daddy

Good answer ^

And now from my own experience if you have a tank with low depth like say 18 inches a t5 54w fixture may grow sps however for a deeper depth it will keep stuff alive but not thrive!

I had a 6 bulb tek over my 120g with 2 extra single t5's full sps tank and in 3 months went back to 2x250w hqi. While some sps did well with t5 at the 8in and up mark the rest coloured down, so IMO mh hqi with sps FTW!!!!!

Ha, i see you have the fixture I am considering for sale....lol
what bulbs were you running tang daddy?
and you say you had 2 extra on there?
so you really had 8 t5's with individual reflectors all in all and were not satisfied?
what are the dimensions of your 120 if you please?
you're comparable experience is precisely what I was hoping to hear

[parkinsn]

Just putting this out there
http://www.canreef.com/vbulletin/sho...threadid=51991

Anyway on a serious note, great response Myka, that about sums it up.

[Powertec]

I use both MH and T5.
I can honestly say I can keep the same SPS corals on the bottom of my 24 inch deep tank and the color is just as good. IMO dont worry so much on lighting there is much more that influence color in a tank than just lighting.
You can drive yourself crazy there are many tanks on both sides of the debate that are impressive.

[lorenz0]

canreef is dominated by people who believe that MH is the only way to go. IMO MH is good for growing but color is a whole different story. Still can NOT get the same colors that you can with T5's (edit) unless you run 22k MH but than your losing your growth

Its all up to you really, personally i prefer T5's and will never own MH.... but the temptation has been there to try them out

[gobytron]

Myka

holy smokes, I just looked at your photos from yesterday.
That is one nice 33 gallon.

what do you have for fish in there?

did you decide to go skimmerless to have more nutrients since you're predominantly lps?

your fox coral look angelic....

[Doug]

Ha, trying to grow sps under T-5 lighting. Now thats a joke.

http://reefcentral.com/forums/showth...5&pagenumber=1

I usually dont like linking another forum but some outstanding sps aquariums in this thread. Not sure of the depths without reading it again but some I know for sure are that deep or close to it.