Too Much Light?? Joe I need you!!

[garrettjohnson]

I was wondering if their is such thing as to much light??? I have a 55 gallon tank, and I am planning on keeping mainly only LPS hard corals and maybe some clams. Would 2- 250 watt MH's be to much light to place LPS corals such as brain, and bubble and candy cane corals at the top of the tank??

[fishdoc11]

It would not be too much light but it is overkill for lps corals. The VHO's you have now should work just fine. I have 4 110 watters on my 55 and they do a great job with even sps although the growth isn't what it is in my 75. Also you will not have near the heat issues with VHO's as you will with MH. As far as clams you could probably keep squamosas and deresas but maximas and croceas would be iffy.
Chris

[Sir Knight]

Hi Garrett,
I think I answered this on ETRC,
Here was my response

"I would recommend 2 - 250 watters if you want to keep the light demanding clams such as T. Crocea and maxima and the high light demanding acro's. I am recommending the 250 watter vs the 175's for the simple reason, if you get the 250 watter and you have a little too much light to start, you can raise the lights higher from the water surface. If you get the 175's and you need more light, you will have to replace the lighting. Also if you can get the pendants go with them vs retro's, it will make it easier to move than up or down as needed. I recommend either Sunlight Supply or PFO. I would get the pulse start ballast's, this will give you more options as far as bulbs."

NEW response:

Yes, you can have too much light for LPS corals but to keep the clams that I have named above you will need 250 watters to keep them happy. If you go with the less light demanding clams like Squamosa or hippo's than you can get away with the 150’s or 175’s watt MH lighting or even VHO or T5's. Keep in mind that these clams get big. I don’t like keeping clams without some kind of MH but that is just me. I have tried VHO's and clams and could not keep them alive for more than a couple of months, however with MH I have kept clams alive and growing for years.

To help a little, think of it this way. If you go with the 2- 250 watters pendants all you would need to do is raise the pendants a little higher then normal (3� to 6" above the water is normal) say 12" above the tank. Then later on, if you wanted to add, lets say an Acro or one of the other more light demanding SPS or for that matter one of the light demanding soft corals and yes there are some soft corals that require a lot of light to look their best or one of the more light demanding clams, you can just lower the lights and rearrange the LPS corals down lower in the tank. My favorite color is blue so the 20000k radiums would be the bulbs I would recommend. They are more subdued and are not as bright as say the 10000k Ushio bulbs. They also give the corals a really nice look IMO. The other advantage is you will not need any actinic supplement.

One last comment: If at some point you get a bigger tank like a 90 gallon and you buy the 250's now, you would not need to replace your lighting. The 250's would be just fine whereas the 150's or 175's will not work at the lower levels of your tank

Hope this answers some of your questions. If not, feel free to email me and I will try to get into more details.

[wooglin]

My take is that there is no bulb on the market that comes anywhere close to the light intensity and power of natural sunlight at 20 feet under water, much less the 2-3 feet out tanks are in depth. There are some interesting articles over on reefs.org about the PAR of various halides measured in the tank, versus the sun. You will be very suprised, I was.

Here is a link to an amazing article.

http://www.advancedaquarist.com/issues/august2003/feature.htm


The short is that that on a 120 with 2x400 watt bulbs the par is about 1200 before it even enters the water. 4-5 inches into the water it is around 450.

In the wild the par at 3.2 feet is 1800, 6.4 feet 1600, 9.6 feet 1444, at 32 feet it is still an amazing 670. Much higher than what even the most powerful halides we have can provide at 6 inches into our tanks.

[Sir Knight]

I read this article last year and did find it quite interesting, We keep trying to create natural sunlight in our tanks, but no one comes up with anything like now much light does a given coral need until it reaches total saturation. A good example is a Palau Sinularia tree coral (which is one of the light demanding soft corals) when I kept them under 400 watt MH or for that matter 3" under the water with 250's, when the light first came on they would open up taking in the lighting, as the hours went by they would start closing for a bit then reopen and so on, could this be because they reached their saturation point? Also the same thing was going on in my greenhouse in TN on clear days. My greenhouse covering allowed 95% percent of the UV thru.

What researchers should do IMO, is when they measure light levels on the reef, is take into account that it isn't always high noon and clear, there are cloudy days, clouds passing over head, rainy days, water clarity changes thru out the year and so on. All they do is take a meter out on a clear day at high noon or for a couple of hours and say this is what we need to match. If that really was the case, we shouldn't be able to keep any coral that was collected in less than 30 to 50 feet of water, unless we ran 1000 watters per two feet of water. Maybe we compensate by the number of hours we keep our low level light lighting on, not have to deal with cloudy days over our tanks, feeding, keeping our water clarity levels high, etc.

Just something to add to the equation that will help us look at lighting our tanks vs natual tropical sun from a different stand point.

[reefstyle]

You can run 1000 watt mh but the heat would be through the roof. It is based the problem we all do buying corals for looks, not can they go together or even the same water conditions. We stick leathers with lps,sps, ect... In a perfect tank we should do same
kind of corals that use the same water conditions, lighting and flow rate. No matter what the tank size is its still inches from the light and what does it need. Researching the coral first is the best and having a game plan where you would like to go would stop future problems. IMO help this helps dennis :D