Watts Per Gallon?

[sonewfish]

What is the appropriate wattage per gallon to keep acropora? Also can you place halides close to the water if you have a good chiller?

 

[007]

Watt's per gallon is a useless rule . . . . it is completely meaningless. Yes you can place halides too close to the water, even with a chiller.

 

[sonewfish]

OK! Well, if you had a choice between the coralife aqualight pro HQI at 492watts or the Current Outer Orbit HQI at 560 watts, which would you buy? I do not have much clearance under my canopy. It is right at 5 inches. I am currently running a coralife lunar aqualight at 260 watts. I also have a 1/10 hp JBJ Chiller. I want to have acropora corals. What do you suggest?
The Current outer orbit is 4.25" tall while the aqualight is just 2.75" tall. The aqua light would give me better ventilation I know, but the orbit has more wattage.
Tank Demensions:
48w x 26h x 24d 120 gallons

 

[diadema]

the height of the fixure isn't as important as the actual distance of the bulb from the water. The taller fixture might just have a deeper reflector, and not be closer.
a 5" clearance canopy is gonna be really tough.

 

[sonewfish]

No matter which fixture I go with I am looking at a distance of 3"+/- from the surface of the water. This is why I bought a chiller. What would you go with. It is an All-Glass canopy so surely they took into account that I may want to use halides!

 

[oceana]

cant you just make a new rim for your hood to sit on your tank. simply cut some planks out of oak or pine depending on what you hood is made out of and make it taller. make it look like molding . i will give you clearance you need and look nice to

 

[dburr]

Originally Posted by SONEWFISH
No matter which fixture I go with I am looking at a distance of 3"+/- from the surface of the water. This is why I bought a chiller. What would you go with. It is an All-Glass canopy so surely they took into account that I may want to use halides!
3" from the water is really close for MH. I wouldn't go less than 6". Mine are at 9". Splash could crack the bulb.
I assume the canopies are DE bulbs?? You didn't say. They will have a shield and I hope you will have an open tank also.

 

[sonewfish]

They are DE bulbs and it does have a sheild. I was going to remove the glass tops after I got it. Do I still have to worry about fish jumping out though? If I attach the ligh to the canopy I my be able to get 4-5 inches from the surface, not sure though.

 

[trompet3]

Watt's per gallon is a useless rule . . . . it is completely meaningless.
With the concensus now being that PAR is the important factor, I have not been able to find anywhere how much PAR you need per gallon or if not per gallon, then any calculation to determine how much PAR is needed. How do we determine how much is enough?

 

[sonewfish]

What is PAR?

 

[trompet3]

Originally Posted by SONEWFISH
What is PAR?
Photosynthetically-active radiation

 

[dburr]

NO SHIELD???!!! Are you sure? DE need a UV shield.

 

[sonewfish]

No. I said it does come with a shield!

 

[dburr]

Originally Posted by SONEWFISH
No. I said it does come with a shield!
oops, my bad. If you can get it up to your 4-5" go for it. But, you may have to claen that glass pretty often. I always get spots on my SE bulbs. I think it's the fish time to time splashing them.
It sounds like theirs not much difference in the wattage of the 2 your looking at. Don't know much about either brand either. Sorry. I would go with the one that backs their product. (longer warranty)
HTH

 

[sonewfish]

Thanks for the input! I finally decided to go with the coralife HQI. I t has alittle less wattage but gives me better clearance.

 

[trompet3]

Originally Posted by trompet3
With the concensus now being that PAR is the important factor, I have not been able to find anywhere how much PAR you need per gallon or if not per gallon, then any calculation to determine how much PAR is needed. How do we determine how much is enough?
anyone?

 

[pyro]

From what I've heard, the only way to determine PAR is with an instrument. I think it's a luxmeter or something along those lines; maybe a parmeter. Not sure. But I dont' think there is an easy way to do it.

 

[trompet3]

Yes, that's true, but a lot of bulbs have been tested and their results with various ballasts are known. So, knowing the PAR is one thing, but how does that correlate to how much is needed?

 

[diadema]

For what it's worth - i had a 'modern series' canopy. I assume that's the kind you have. I ran 175W SE MH retrofit. The actual distance from the water was less than 3". Didn't overheat - I did run a pair of 65 CFM fans and I keep my AC at 74.
You can also enlarge the canopy - I did it when I added a 400W Radium.

 

[yeffre kix]

I wouldn't have the glass cover of the light any closer than 6". Even that's a little close. You'll be continually cleaning the salt buildup off of the lights. Making the canopy a few inches taller will also give a more appealing ripple effect from the MH's with little loss of light intensity.