T5 Par & Bulb Selection

[StirCrazy]

Originally Posted by Der_Iron_Chef

Yeah, but comparing a 250W MH bulb to a single 39W T5 bulb isn't the point, is it? It's comparing comparable output and their PAR values, no?

nope, single bulb to single bulb is the only proper way to compare intensity, we are not talking about coverage or average PAR or total PAR over a tank, we need to look at what is important, PAR intensity at a single point and every time a MH will win that argument.

Steve

[Der_Iron_Chef]

Originally Posted by StirCrazy

nope, single bulb to single bulb is the only proper way to compare intensity, we are not talking about coverage or average PAR or total PAR over a tank, we need to look at what is important, PAR intensity at a single point and every time a MH will win that argument.

Steve

That doesn't make sense to me at all. Why is PAR intensity at a single point more important? Why isn't coverage and average PAR, or total PAR over a tank? It seems like a really biased way to test things, since MH is designed to be intense at a single point (relatively speaking).

It's also not practical for what we do. We don't want PAR at a single point. We want PAR throughout the aquarium. At least I do.

But back to original idea of T5 PAR and Bulb selection, PLEASE!! I have no desire to see this become a MH vs. T5 debacle.

[StirCrazy]

simple. intensity will tell you how far you can penetrate, if tests are done properly you will see that light has 1 constant for the amount it decreases in intensity for a distance traveled.

so by being able to compare intensity we can determine the depth we will have suitable lighting at.

the T5s do have a bonus and that is uniform coverage, but that is at a cost. less intensity. it is the same as VHO, PC, NO ect.. as I have stated before a PC is brighter and more intense than a NO T5 as a PC is actually a T4, but don't get confused with the smaller tube size being better. that holds true for a given wattage. so we would have to relay compare a high output T5 to a VHO. the T5 will be better than the VHO, but I would guess by only 15 to 20%. the big advantage is size which allows you to put more wattage under the hood and a more even lighting.

But even this comes with a cost, with florescent tubes the smaller the size with the same wattage the more intense and the more heat that is produced, fluorescents main enemy is heat and as a result really impacts bulb life. as we saw one poster int hat post stated that they shift more red in 3 months so you should change the bulbs that often. so 4 changes per year compared to 1.5 for VHO/PC and 1 to .75 for MH. Also if you set up your MH properly you will get an average 2x2 coverage that will give you bottom PAR values than T5 with no problem.

the main difference is that lets say you have 1 T5 tube in say 14" of water and it has a bottom value of say 100 (just to pick a number) you now add 10 more tubes under that hood and you bottom value is still 100, just more of the bottom has that value. so you have not increased your intensity at all by adding tubes only the coverage which is a good thing, don't get me wrong. but now if you take that same 2x 4 tank with two good reflector SE MH you will find you have a bottom par of say 400 or higher (in relation to the other number) over 70% of the bottom and say 200 to 400 in 20% and 100 in 10%. over all the MH will pump a way higher average but it will not be evenly spread which is good also as it alows you to mix very high light corals with ones that don't like so much.

now having said all this we had a guy grow some colored SPS under NO's granted he had them high up and the growth was slow but they did have colour. so any light can work, it just depends on your overall goal and the method you want to take to get there. but changing 500 watts of MH bulbs once a year is a heck of a lot cheaper than changing 500 watts of T5 bulbs twice a year.

Steve

[fkshiu]

Anyhooooo,

back when I had my 4x39W Teklight my bulb arrangement was this:

FRONT
G-man actinic
Coralvue 10K
Coralvue 10K
G-man actinic+
BACK

The Coralvues are kinda crappy and yellow but I guess the got the job done and they're cheaper. G-man's are good bulbs and I think offset the yellow of the coralvues very well.

That Grimreefer's thread that you linked previously contains a wealth of information if you have the patience to sift through it.

I'm now using 3x175w MH w/PC actinics over my 6-footer. I plan on switching to an "overkill" setup using 250w HQI (XM 10K) with 2x80W T5HO (G-man actinic+) and 2x160W VHO (UVL super actinics) in the very near future. I hope to get the best of all worlds with this setup: the PAR and penetration of the 10K MH bulb, the blue spectrum of the T5 and the actinic pop of the VHO.

For the record, the had the T5 bulbs in the teklight for almost 18 months without changing them and I did not notice any noticeable degradation in light output/colour over that time and the corals (LPS/softies) did not seem to "sag" at any point.

[sphelps]

I've been running T5s for a while now on a few different setups. The best bulbs available to us in Canada are the ATI line up, they produce the highest par ratings that I have seen compared to other bulbs.

The most common bulbs used are the;
Aquablue special (around 14000K), if you like whiter tanks this bulb alone will produce the color you like.
Blue + (around 22000K), basically just a bright blue bulb, you can add a few of these to create a more blue tank, I believe a 50/50 mix of the blue+ and aquablue will create similar color as a 20K halide.

Also new from ATI are 2 new bulbs;
A Pure Actinic which has a pink/purple glow and acts much like a black light making corals glow, however I've found similar pure actinic bulbs to be drowned out by the much brighter other bulbs.
A new daylight, similar to the aquablue special but is said to have a 5% red spectrum just like the KZ coral light bulb. The extra red gives some more color pop from opposite colors like blue, purple and green.

HTH