light height off my tank?

[Wiskey]

<a href=showthread.php?s=&postid=6545166#post6545166 target=_blank>Originally posted</a> by finneganswake
Ok, where is everyone getting the idea that he'd even need a 250? From the people who sell the lights? Anthony Calfo, who recommends that everyone have a PAR meter, says a 250 is only necessary if the tank is around 36" deep, and that a 400 is rarely necessary and should only be used after checking the PAR levels in advance. Maybe a 175 would be necessary for a 90, but even 250 is overkill. I've got a 150W 10k on my 50g, and I've got seriously light-demanding corals that keep their color very well, IMO much better color than from the place where I've purchased some of them that uses 3 400W 20k on a 180g--his colors aren't bad, but they aren't as deep as they could be (a little pale) if he lowered the light levels a bit. Am I the only person on this board that understands photo-inhibition?

Photo inabition is not all we are talking about here. 400W means NOTHING, :lol: that is like compairing W/G. The 250W XM 10K bulb has more par than some of the 400W bulbs out there. To compar lights we need par readings from diffrent levels in the tank, then we can start talking about photo inabition.

Whiskey

 

[Reeling Reefer]

"has the world lost all common sence and the ability to think/work things out for themselfs". Jent46bow, themselfs? What kind of BS is that? The only stupid questions is the one that is not asked. If you don't like the question or think its to elementary, then pass it by. To be critical of someone looking for help is the ultimate sign of ignorance.

 

[finneganswake]

<a href=showthread.php?s=&postid=6545223#post6545223 target=_blank>Originally posted</a> by Wiskey
Photo inabition is not all we are talking about here. 400W means NOTHING, :lol: that is like compairing W/G. The 250W XM 10K bulb has more par than some of the 400W bulbs out there. To compar lights we need par readings from diffrent levels in the tank, then we can start talking about photo inabition.

Whiskey

I agree with you that 400W isn't as useful as a PAR reading, but let's be honest--400W is too much light for most tanks coming from a guy (Anthony Calfo) who's probably taken more PAR readings than 30 or 40 of us put together. Most people who buy 400W bulbs are only doing it because they assume that bigger is always better. People on this sight parade their 400W bulbs like trophies

Besides, if you read the post a bit more closely, you'll see that I'm talking about watts in relation to tank depth, not watts per gallon.

 

[finneganswake]

<a href=showthread.php?s=&postid=6545201#post6545201 target=_blank>Originally posted</a> by physicslord
90G tank.

2 250W would give a little over 5W per gallon. How is that overkill? Isn't that what everyone reccomends?

Watts per gallon is a useless measure, as it doesn't take tank depth into consideration. A 70g tall needs much more light than a shallow 150g. I've got a standard 50g with a 150W 10k and 2 65W PC actinics, which comes pretty close to the 5W per gallon and it's bright enough that I have had some sps bleach due to photo-inhibition until I moved them lower in the tank. This could be because 10k bulbs are much brighter than 20k, which seem to be the most popular bulbs.

 

[Wiskey]

<a href=showthread.php?s=&postid=6545508#post6545508 target=_blank>Originally posted</a> by finneganswake
I agree with you that 400W isn't as useful as a PAR reading, but let's be honest--400W is too much light for most tanks coming from a guy (Anthony Calfo) who's probably taken more PAR readings than 30 or 40 of us put together. Most people who buy 400W bulbs are only doing it because they assume that bigger is always better. People on this sight parade their 400W bulbs like trophies

Besides, if you read the post a bit more closely, you'll see that I'm talking about watts in relation to tank depth, not watts per gallon.

I know you wern't talking about W/G but without knowing the bulb type I was saying that 400W to x tank depth was just about as meaningless.

You are right though, most people W/ 400W fixtures did get them by that mindset, but not all. I just got a light meater myself, and using it I was able to find out that my light was not what I thought it was.

I was using a 250W XM 10K over a 4 foot tank, and although it looked bright all over, I found that I was not getting the light I needed anywhere. I have changed to 2*250 10K 12 inches off the water. 2 *150 would have been fine for my tank, but I plan to upgrade soon, so I figured I may as well get the setup I will need now, and just run the bulbs high up until I get the bigger tank.

Whiskey

 

[Joboo]

wnutz,

I have a 90g and I use:

2 - 250w Ushio 10k
2 - Super Actinic VHO 110w bulbs
2 - 50/50 VHO 110w bulbs

Lights are on for about 10hrs with the actinics coming on first then 1hr later the 50/50's and finally the MH's 1hr after the 50/50's. I have ran this way for almost 2 years with no issues.

I made a custom canopy that allows me to adjust the height but I have always kept them about 12 inches above the water. I do have the ability to put them as low as 6" off and as high as 16" off the water. I have no issues keeping Soft, LPS, SPS or clams.

Since you have 150w MH's you may want to lower your lights a little bit. Maybe 8-10 inches? See how that works and adjusts from there. I think most of this is trial and error so you may want to experiment with it.

What do you plan on keeping? If you want to keep SPS and a few clams you may want to look into more lighting. If you are going soft/lps then I think you'll be ok.

 

[wnutz]

thanks for all the good responses i was starting to get worried that the aqualight pro i bought was a waiste of mone they told me i could have a mixed reef with them and the actually had the on all their tanks and they seemed fine i changed the coralife bulbs to aqualine 10k and some of my corals were bleaching so i figured the light was burning them so i wanted to know the height i have them about 71/4 inches now they were 5inches because i just used the legs that came with the light. the light consist of 2 150w 10k aqualine and 2 96w actnic again thanks to everyone who had something positive to say.