why does everyone thing 8 t5s is too much light?

[nemo g]

ive seen post after post advising new t5 users to stay away from 6 bulb and definitely 8 bulb teks if there are going to do any lps and shrooms.

where did this fear come from?

ive got an lfs with a 75g and a 6 bulb tek light, with nothing in it but softies. xenia, cloves, shrooms, ricordia, sponges, star polyps, and others.

if all this can live with a 6 bulb tek, as well as live under halides, why is everyone so adamant that 8 an bulb tek is way too much for anything less than sps???

hmmm...

[WorldNation]

i dont think thats too much at all.

[benjonesn]

Frankly I'm more than a little disappointed with the light from my 4' 4 bulb Tek over a 72 bow. Maybe it's my bulb choice or that I'm running stock ballasts. At any rate, out of the box it's only intense enough to moderately maintain sps colors in the top 8 inches or so of the tank. I don't see how anyone could say T5s are too intense at any sort of water depth. I've seen the posts too though.

[SWfan]

I've got the 6 bulb over my 75. I can keep sps on the sandbed the light is so intense. The 8 bulb would be ridiculously bright. Not to mention that the two outside bulbs would hang over the front and back of a 72. Wasted spillover IMO.

I had to raise my light from 2" above the tank to 10" above the tank. My T5's are not overdriven either.

[maddyfish]

The 6 bulb t5 that I've seen on a 90 wasn't overly impressive. Probably could have used an 8 bulb.

[moonpod]

more is not always better. HOWEVER, with T5s, IMO a lot has to do with number of bulbs over what size tank dimension b/c "coverage" is sort of an issue b/c you don't get great spread necessarily. First hand, back in the day, running 5' bulbs on an IC660, (this is 2003 we don't know much about T5) I killed A LOT of animals from having 'em too close to the top. Zoos, LPS etc....BUT like anything else, you can photoadapt your animals and have success.

Basically, your mileage will vary. Every setup has its own individual peculiarities. IMO you should strive for the appropriate amount of light over your setup given your needs b/c more just equals more heat and electrical consumption.

[bllfish]

I have the same setup as you, 4 54W with standard tek ballasts on a 72 bowfront and there is plenty of light. Granted, if you want to keep SPS I think they should be over driven with the ice cap ballasts but for LPS and softies the standards should be plenty.
I used to have 6 65W PC and these lights are way brighter - no comparison at all and my corals are growing much faster.
What bulb combo are you using?
Do you have the individual reflectors?

[The Beaut]

I have a 6 bulb tek over my 55gal. Way to much light, bleached all my corals when i put it on. That is why some people caution others about them. Slow acclimation is the key to not damaging your corals. Now that all my corals have recovered i only run 4 bulbs.

[raskal311]

I put sps frags 4" from the top of the water running 400watt MH and I dont have any problem. Are T5 that bright?

[bllfish]

I believe if you do a search you will find that the only difference between T5 & MH are the shimmer lines. I do not keep SPS so I am no expert but I have read many threads on RC where people are having great success keeping SPS under overdriven T5s

[tanku]

i have an 8 bulb on my 90. at first my shrooms did not like it but now the are multiplying at a fast rate. everything else transitioned well. i have 2 6500, 3 actinic plus, and 3 blue plus. it creates a real nice blue/white color.

[bllfish]

On my 4 bulb I have front to back
blue+, ultra blue, GE6500 daylight, blue+

[RichConley]

Originally posted by benjonesn
Frankly I'm more than a little disappointed with the light from my 4' 4 bulb Tek over a 72 bow. Maybe it's my bulb choice or that I'm running stock ballasts. At any rate, out of the box it's only intense enough to moderately maintain sps colors in the top 8 inches or so of the tank. I don't see how anyone could say T5s are too intense at any sort of water depth. I've seen the posts too though.

Thats got nothing to do with light then. There are a bunch of TOTM quality SPS 75g tanks running on 4 bulb tek fixtures. If you can't keep your corals colored up, its most likely nutrient issues.

[nemo g]

on a "standard" reef tank, 18" is the norm due to the improved aquascaping.

8 bulbs, within a tek fixture, would only be 14" wide, the rest would be fixture, of which less than 1/2" would be "hanging off". and only if it is perfectly centered. move it a 1/2" back, and its perfectly flush with the fron of the tank. so, its only "wasted spillover" on 12" tanks, which wont ever concern me.

nonetheless, the bulbs will be far inside the lip of the tank. just look at the edge of your ficture and youll see that is has about 2 inches of "edging" on each side before getting to the reflectors.

as far as "too much" goes, i plan on using a pair of actinics which are low par so it shouldnt be an issue.

i figure itll give me a lot more bulb combo options, as well as the ability to not use a pair of bulbs if it was "too much" or the ability to add extra par if i needed more (ie mainly sps).

just odd how for months of asking myself the same question, and readings hundreds of posts saying 6 was too much for softies and lps, that it finally occured to me that the only tank in town with a tek light on it had 6 bulbs with nothing but softies in it with the occasional monti frag.

im beginning to think its more of an aclimation issue. tons of zoos and shrooms are found in shallow areas where they can be exposed during low tide, which means they are used to getting tons o light. but after shipping from distributor to distributor, then lfs stores, and being placed in lower light situations (because they tolerate it well), they probably get shocked when returned to high light areas.

enough of my arm chair marine biology and back to the books.

[bllfish]

Does the 14" include the reflectors? My hood is 12" wide and I could only fit 4 bulbs with the retro kit and the individual ice cap reflectors..

[DaveG99]

I think a lot has to do with the quality of the t5's. If you get the ebay t5's then it wont be as bright as a reefgeek setup. The higher quality reflectors you get the less bulbs needed. I plan on getting the 4x80watt 60" retro kit from reefgeek and I hope it is enough for my 125 gallon.

[geckofrog]

I prefer MH's over T5's for the shimmering effect, looks like the real ocean

[davocean]

i've seen alot of people saying it has alot to do with the reflectors
Single reflectors make the light way more intense.
People not getting enough brightness may try single reflector retro's

[nemo g]

guess you guys missed the "its a tek light" bit of info

from my measurements, the reflector is 1 3/4" wide, thus 8 = c. 14" whether its in a tek hood or retro setup.

ice caps are wider, and i think designed with a more focused light spread than the teks (from looking at the reflector pics).

why does everyone feel a need to share completely irrelavent halide information, especially that which is purely subjective, in every t5 thread???

yes halides have shimmer. i used to have a need for it, now i dont. in fact, i find that repetition in the shimmer pattern very annoying and distracting, especially smaller faster lines.

so for future reference, try and keep thread responses some what on topic. i for one will greatly appreciate it

[sjm817]

I have 6 over a 90G (retro w/ice cap reflectors).
Shrooms on the bottom..forget it. All shriveled up. My Monti Cap about 2/3 up was bleaching too.

I was running a 50/50 mix of Aquablue and Blue+ To reduce output and get more color, I changed to 2AB, 2B+ and 2UVL SA. Still too much for the shrooms (dont care about them anyway), but the cap is starting to color back up.

FWIW, I dont like shimmer lines. I find them very distracting. I do like how a Halide lit tank has light and shadowed areas. A T5 tank is very uniformly lit. JMO.

[nemo g]

sj, about t5s and shadows,

i think it gives us a bit more flexibility. for example, with a halide, especially a solo, you have to be very direct about aquascaping or shadows easily show up. the live rock has to be staggered like a stair case in order to get proper spead of illumination.

however, with t5s, thats not an issue, so one can be more creative with aquascaping and not worry about creating spots that dont get good light, since even corners will get the same amount. which means, rock caves and lower light areas can be created where we want them, not where the halide creates them.

make sense?

[old salty]

Nemo g,

Take a look at the pic below and spot the red mushrooms at the bottom of the tank. They are way down there in a semi - shadowed aread as the T5's are causing them to shrivel up anywhere else. Notice how far down I can place SPS and so far, so good. This is with 6 bulbs, though I wish I did get 8.

[Ixthys]

I've got an 8 bulb 54w staggered configuration over a 215g tank (6 foot wide, 29 inches deep) with IC660s overdriving them. Its been up for a month, so I am clearly still trying to figure things out. Here are a few observations:

-hairy shrooms on far left side, on bottom, at the fring of the bulbs, partially blocked by overhanging rocks are doing great.

-new shrooms (1 wk in tank) on far right side on bottom facing the front glass are shriveled up. Will give them another week before moving.

-Acans about 1/2 way up, on side (only 4 bulbs directly over them) are doing great. New Acan in middle of tank (8 bulbs) 1/2 way up still hasn't declared itself.

-Acros were put at top of rockwork (2/3rds way up) and are starting to grow (after the shock of being stored/moved).

-Orange Monti inadvertently left on bottom of tank for few days did not like that! Now at top of tank and thinking about getting some color back.

-Clam on bottom (under 8 bulbs) seems to be doing well.

Anyway, just a few observations. I need to give the tank a few weeks of not messing with it so that I can truly see what everyone likes!

[sjm817]

Originally posted by nemo g
sj, about t5s and shadows,

i think it gives us a bit more flexibility. for example, with a halide, especially a solo, you have to be very direct about aquascaping or shadows easily show up. the live rock has to be staggered like a stair case in order to get proper spead of illumination.

however, with t5s, thats not an issue, so one can be more creative with aquascaping and not worry about creating spots that dont get good light, since even corners will get the same amount. which means, rock caves and lower light areas can be created where we want them, not where the halide creates them.

make sense?

I know what you are saying, but it is different. Halides just have a different look that you cant get with T5s. The Halide tank has lots of light intensity variations all over the tank, whereas the T5 look is very uniform irrespective of aquascaping. Spots that get different amounts of light and the shadows are not a bad thing. To me, it is a nice look that I can not get with my T5s since they are not point source lighting. Part of it may be that my T5s are only ~ 4" off the water. If they were @ maybe 6" or so, it might look a little different. I have plans to go to a 120 in a peninsula setup. I'll likely have the lights higher on that tank.

This is off topic, but getting back to the original post, I would not use 8 bulbs over a 75 unless you had nothing but very high demand SPS and then you would have to be careful.

[bllfish]

Could you add some screening between the lights and the tank to diffuse light in certain areas?