Is there such thing as too much lighting???

[IronRising]

Hey guys :biggrin:

Got another question for ya. I'm trying to plan out my lighting set up for my 90 gallon reef tank, and my biggest concern is my lighting. LFS always mention minimums (i.e tank size, filters/sump, watts) but is there such a thing as too much. Right now I'm looking at getting a Tek light 48" 8x54 bulb for a total of 432 watts, which gives me 4.8 watts per gallon. I'm pretty sure that's not over doing it but if i decided to add some supplemental lighing for color... what is too much???

[Aquattro]

I run 800w over my 18" deep 90, so you've got a ways to go to hit "too much" :)

[Bloodasp]

anything brighter than the sun or maybe one that uses power enough to light half the city. :p

[lastlight]

More a case of potentially too much light too fast. I don't think with either t5 or mh you can fit more light physically than most coral can be acclimated to.

[Delphinus]

+1 .. Acclimation is key when transferring from one intensity level to another.

More a case of potentially too much light too fast.

[Jack]

http://www.youtube.com/watch?v=mfcLNj6m9tA

[ScubaSteve]

There is, however, a maximum amount of light that corals can use. This level is called the saturation point, beyond which you start to get photoinhibition. I had the same question a while ago.

Look at Advanced Aquarist Magazine online; they have a lot of articles on this topic, particularly with respect to different algae clades. As stated above, too much light too fast = bad and lots of light can be good for growth, but there is a point where you start to get decreasing returns on the amount of energy you're pumping into the tank.

[Murminator]

I used to run a 400W MH over a 29G It did good

[Bloodasp]

Aside from what was said. Another issue that would arise would be the heat that the fixture produces.

[IronRising]

This tank is a basement dweller, so heat is a little bit easier to control. A couple fans should be able to fix that. Thanks for the video Jack! The only thing i was worried about was maybe bleaching some corals.

More a case of potentially too much light too fast. I don't think with either t5 or mh you can fit more light physically than most coral can be acclimated to.

While i don't have to worry about that as you stated t5 is not an issue. I have never even been told about light "acclimation" thanks!

[StirCrazy]

There is, however, a maximum amount of light that corals can use. This level is called the saturation point, beyond which you start to get photoinhibition. I had the same question a while ago.

Look at Advanced Aquarist Magazine online; they have a lot of articles on this topic, particularly with respect to different algae clades. As stated above, too much light too fast = bad and lots of light can be good for growth, but there is a point where you start to get decreasing returns on the amount of energy you're pumping into the tank.

you know we have been reading about this for about 6 or 8 years now and I have yet to see anyone one in real life that didn't get an increase in growth from better lights..

I think what people are confusing is that it takes a lot more light than we can give for an actual decrease in growth.. after all can we match the suns intensity for 8 hours? nope.

Now I do think we will see a point where there is no benifit to running your MH longer.. for instance, I used to run my MH 10 hours a day and the actinics 14 hours a day. I bumped up the MH to 12 hours but I didn't see a noticable increase in growth over a month so I went back to 10 hours, at 8 hours there wasn't as much growth as 10 hours. but I did not see a decline in growth from going to a longer period only that the growth remained constant.

but back to the original question Watt/gal is totaly useless and anyone who mentions it (as in a LFS) should be slapped as all it does is confuse people and allow inferior lighting to be sold and made to look better than it is. (I'll explain this in a bit so you understand what I am getting at)

now with T5's you will never reach a "To much light" situation so go ahead and add away.

Now to explaine my styance on watt/gal. I have explained this several times over the years but I won't make you search for it. because there are lots of newer people who have probably never heard it also.

there are two reasons why Watt/gal is useless the first one being light intensity and dept of penatration. I'll explain further.

take two tanks. say both are 10 gal and well say one is 4" deep 12" wide and 48" long. and the other one is 24" deep 12" long and 8" wide

put the same 50 watt light bulb above them and they both have 5 watts/gal, but is the light getting to the bottom of the tank the same?

not even close, you could probably grow SPS in the 4" tank, but would be lucky to grow mushrooms in the 24" tank.

the next reason is the quality of the light itself. now I don't want to turn this into a MH/T5/LED/Plasma/ect battle so I will use NO and VHO lighting in my example.

so this time you have two identicle tanks.. say 20 gal tanks 6 wide x12 deep x48 long.

over one you have three 32 watt NO bulbs for a total of 96 watts, over the other you have 1, 96 watt VHO. the intensity of the bulbs are different the VHO has a lot more depth at the bottom of the tank. to give you an example on a 12" deep tank a NO day light bulb was producing 18 PAR units, where a VHO was over 200.

so these tank have identicle watts/gal. but because the bulbs are different types the intensities are way different resulting in the NO lit bulb not much usefull for growing anything but algae at the bottom where the VHO in that size of tank would grow SPS.

so this is why I don't like watt/gal.. it is used to much to make products sound better than they are. now there is one place where they are ok. and that is when changing the amount of bulbs over a tank when you are sticking with the same bulb.

Steve