Converting mh hood to t5 hood

[ssreef]

I have a 6'x2'x2' wooden hood. I want to remove all fixtures and bulbs so hood is now empty of lighting.

What I want to do is to install a t5 retro consisting of 6- 80w 5' bulbs. T5 bulbs I have been told should be installed about 3-4 inches above the water. My hood is 10 1/2" in height inside dimension.

Ok now how would you suggest I make something that can be made to be installed 3"-4" above the water and could be lower or pulled back up so I could do servicing, feeding and cleanup etc. without having to take the hood off every time?

I am concerned about warpage and heat. The ability to adjust the height of the bulbs would be a big plus also. Also where would I put a fan to cool the t5 retro in the hood?

Thank you in advance icbic

 

[ssreef]

Sorry did not mean to hit the button twice for a double post

icbic

 

[mr_X]

sorry i can't help you, but i'm really curious why you would want to do away with metal halide lighting?
are you considering selling the old MH guts from your hood?
i'd be interested

 

[ssreef]

The reason I am switching from mhs + vho on my 180gal is that I no longer have many sps and have started keeping lps and softies. I just got tired after 9 yrs of sps.

I live in Fl and the temperature on my porch with mhs +vho and a cooler running 25 minutes every hour for 10 hours a day is very expensive.

So I have heard that t5 give off very little heat compared to mhs +vho and will keep sps and lps alive and growing. The more I hear about the t5 the more I like them. The information I am talking about is from other boards and a couple of people using them if my area.

As of now the 2 mh ballast are from Hamilton and are 400w and I have a 440 icecap. I will keep this setup until I see how the t5 are doing. If all goes well I will probably sell the set up.

 

[wetworx101]

Well, the bad news is that the T5s might not be any dimmer than your 400watt halides. They can outdo halides in many circumstances.

I would do 9 rows of bulbs with Icecap SLR reflectors (2.5" wide reflectors). 3 of the rows should be 5' bulbs which normally run at 80watts, but you can use a Icecap 660 ballast to overdrive them slightly to 100watts each. I am not normally a fan of overdriving, as with 54watt T5s the IC660 ends up running them at 80watts, but the 5' bulbs are only overdriven by 20watts... no big deal. The 3 bulbs you run on this ballast would be daylight bulbs as well... which arent as affected by the overdriving like actinics and blue bulbs. I would run 2 aquablue bulbs by ATI (12,000K) and one 6500K/5000K sun bulb.

As for the rest, I would do a 6x54watt retrofit, staggering the bulbs for coverage. The reason I say 4' rather than 5' is that every T5 bulb kind is made in 4', but only half are made at 5', so having 5' is great for coverage, but for variety... 4' ones added to the mix are a good idea as well. With these 6 bulbs, I would run 4 ATI blue+ bulbs, and 2 UVL super actinics.

And venting is very important. Overheating can rob a T5 of 25% of its output, easily. Even the popular Tek hood isnt vented properly with its passive slots... a fan blowing over the bulbs was shown to boost the output by 20%. The goal is 95degreesC at the bulb. The best way to do this is to draw/blow air across the bulbs somehow... from the ends, or from the back... however you want... just keep the air moving and the bulbs vented. Its not that T5s run hot or anything, but that they are sensitive to the heat they make. Good airflow will keep the output at its highest, and help the bulbs last longer. Recently, the newly imported ATI powermodul was stacked up against the Tek, and with the same bulbs, the ATI pulled 302 at the sand, and the Tek 152!! Active venting is a huge deal.

OR, you could simply buy a fixture rather than retrofit. I would say that a 8x80wattT5 unit from reefgeek would be a great light for a 180g... maybe a 6 bulb system would even be enough for what you wish to do.

 

[Anonymous]

Well, the bad news is that the T5s might not be any dimmer than your 400watt halides. They can outdo halides in many circumstances.

I would not agree with this statement in 99.9% of the cases a 400watt MH bulb will cook as far as intensity goes, even vs 400 watts (7-8 54watt t5s) even with good reflectors, simply because the T5s will be dispersed over a much larger area.

 

[wetworx101]

No. While the halide might have a peak that is much higher close to the bulb (which might be above the water anyways since halides are often mounted 6-12" above the water), the T5s will penetrate deeper thanks to their linear dispersion field. Halides are more of a point source (thats why they give off the 'shimmer').

So what it comes down to is this, watt for watt, the T5s will be more intense the deeper you go, peaking at 1000-1500 close to the bulb, while halides will peak at about double at the surface (depending on the reflector), but they wont carry as deep.

 

[Anonymous]

There was someone who took this idea to the test with an actual par meter, the post was on "the other board" and they showed that t5s were NOT up to the hype that people continuously say, that MH bulbs did infact penetrate deeper.

But no need to go into a full blow debate over this here, the bottom line is if the guy wants less intensity you can go with less t5 bulbs, with metal halides going for "less" usually isn't an option, you can go lower wattage but that means removing a bunch of stuff. With a simple timer you can add multiple levels of intensity as the day goes on with T5s which IMHO is there real selling point.

 

[wetworx101]

Where was this test done? Do you have a link? Most everything I have seen shows T5s shredding Halides in output.

It is entirely possible to have a test that only tests the light field at shallower depths, in which case, halides do win because of their concentrated nature... but I can show other tests (more practical and less biased) where T5s shred halides.

Overall, T5s and halides both have about the same PAR per watt as each other, depending on the color of course (blue T5s are much more efficient than blue halides), but its how they get that light into the tank that makes such a difference. This is where T5s have an edge.

Sure, if I wanted to do a test of halide vs T5 by placing a PAR meter right now under both a halide and T5 bulb, the halide would be the winner... I could take that and run with it, claiming halides to be the superior bulb. But there is more than that. T5s also require more attention to cooling and a proper reflector. In a test of halides vs a Tek light, the Tek came in at about 170 at the sand, and the halide was about 200. Then, the ATI fixture was tested... it had double the intensity at the sand as the Tek... a good 50% higher than the halide! Other things to factor in are ballast, bulb age, K rating, etc. FWIW, when I compare my system of Tek T5s (2x39wattAquablue, 2x39watt actinic03, 2xblue+... not even the brightest combo possible but a near color match to a pheonix 14,000K) to a 250wattDE pheonix 14,000K on PFO/HQI, the T5s are easily brighter.

 

[Anonymous]

I'd find you a link if the search function worked at RC for non-paying members, unfortunately it doesn't, there is a google way to search but unfortunately I forget.

 

[wetworx101]

http://translate.google.com/translate?h ... ult&prev=/

I find the above link, although a German translation, to give a good breakdown of T5 vs. MH

 

[wetworx101]

And here:

http://translate.google.com/translate?h ... ult&prev=/

 

[wetworx101]

At Wiki: T5s are known to generate up to 104 lumens per watt and climbing (currently still under development). The average life of a T5 is much longer than a gas discharge, and this lumen/watt ratio is able to be held much longer.

MH are anywhere from 65-115 lumens per watt. They dont last as long though.

So they are very close. With T5s though, the bluer lamps are able to operate at outputs that are very close to that of the daylight/sun lamps. With halides, this means outputs get cut in half most of the time.

Also, even though the halide may have an at certain points from the raw lumens/watt standpoint, its how these two systems get that light into the tank that makes T5 even more competitive. T5s can be mounted inches from the water surface... not so with halides. T5s are able to get more intensity into the water, rather than waste it with reflectors that have to be mounted 6-12" off the surface... cutting the light even more due to rounded dispersion fields, and the fact that alot of light from a halide has to enter the water at an angle, since the bulb itself is a point source, and almost all the light that comes into the water other than directly vertical from under the reflector has much of its intensity lost as it enters the water dut to reflection. Most halide canopies I see have almost as much light in the canopy as in the tank. The last T5 canopy I saw was dark in comparison.

 

[wetworx101]

http://translate.google.com/translate?h ... ult&prev=/

This page has a good debate going... and FWIW, I agree that perhaps the best light would combine equal parts of MH and T5... to get the best intensity and penetration/coverage of both types of bulbs.

 

[wetworx101]

"Measurements with the lux meter

Before beginning of test we accomplished measurements with a lux meter, which carried completely amazing to day under both sources of light, because the fluorescent lamps surprised us with their efficiency. The again installed 400-W-HQI-Brenner achieved (based on the water surface) centrically the reflector the high value of 52.000 lux. Already under the edge of the reflector this value decreased/went back however on scarcely 22,000 lux. Outside of the reflector range values under 10.000 lux were to be only measured. In contrast to it reached the T5-Röhre, likewise based on the water surface,
a value of 10.000 lux. This increased a good reflector is as important after attachment of the reflectors on approx. 32,000 lux (which clarifies,).

The aquarium arranged a similar impression for us - the achievement of the T5-Röhren was amazing, because the brightness in both aquarium halves was similarly strongly, even under the tubes however than under HQI. Even the soil reason was not darker under the fluorescent lamps than under the HQI burner. Very well illuminating to to the faces of the basin pleased us, because with the lighting by two 400-Watt-HQI-Brenner in our 190 had remained always cm aquarium on the left and on the right shade ranges. After a test run time of six months we would like to describe in the following our experiences with the T5 technology. "

From another test... Just goes to show... apples and oranges. The halide is more intense at the top, near/right under the reflector, but quickly this goes down to levels that are about what a T5 makes at the bulb, across the whole bulb, without the reflector even! Then add the reflector, and you get an even lighting across the whole tank that when added together, means more light for the tank as a whole.