T5 Question: 4 bulb 54w Vs. 8 bulb 39w for a 60 gallon long.

[Moeshi]

Up until now I've been running 4 54w bulbs for my 48 inches long 60 gallon tank. The fixture is exactly 48 inches long as well.

I just recently got my hands on a ATI 8 bulb fixture running 39w bulbs. The fixture is 36 inches long and thus 12 inches too short for my tank. -Or is it?

I've read a ton on the subject and it seems like both options are viable for a sps tank. Currently corals are growing fine, although I'm still working on better colours.
I do realize that colours are the product of a number of things, but I want to hear opinions on weather the 8 bulb fixture would out-perform my current 4 bulb one if I hang it higher to get better light spread.

What do you guys recommend?

Thanks in advance,
M

Edit: I should mention that the current fixture is a DIY Jewel 4 bulb fixture.

 

[Hentz]

How long is your aquascape?

I ran a 24" ATI 6x24 on a 36" 56 gallon tank. Worked perfect because my aquascape was the length of the fixture. Although, my frag rack was slightly suffering because it wasn't getting as much light. So remember that.


While you're only running 4 bulbs, the 8 bulb would absolutely be better because of the coverage, width I mean.

 

[Moeshi]

The aquascape spans the length of the tank. I guess I'll have to keep LPS and softies at the edges then?

The 8 bulb fixture is exactly as wide as the tank, meaning I will have considerable spillage if I raise the fixture too high.

I don't have a PAR meter, but is it correctly assumed that the tank now receives more PAR, but more unevenly distributed? In that case I might be able to work this to my advantage. I want to make sure that the fixture wont bleach the center sps and brown out the outer ones.

Thank you for taking your time to reply.

 

[Hentz]

The aquascape spans the length of the tank. I guess I'll have to keep LPS and softies at the edges then?

The 8 bulb fixture is exactly as wide as the tank, meaning I will have considerable spillage if I raise the fixture too high.

I don't have a PAR meter, but is it correctly assumed that the tank now receives more PAR, but more unevenly distributed? In that case I might be able to work this to my advantage. I want to make sure that the fixture wont bleach the center sps and brown out the outer ones.

Thank you for taking your time to reply.

Personally, I wouldn't mind the sides of the tank to not be covered by the fixture itself. It gives you room to get in the tank, clean pumps, and even add water to when doing a water change. Now in that case, like my 6x24 on my tank, it too was as wide as the tank. That being said, the acroporas within the length of the fixture will receive light from all angles rather than just partial (4x54 bulb). This is a really really good thing, especially when they begin to colonize, because you're decreasing the amount of shadowing and increasing the amount of light penetration to the coral.

Let the light spill! If it is way too much for you to handle, build a little canopy. This can be done easy. Build a canopy like I did in the link, I called it the Stupid Simply Canopy. It literally took me 1-2 hours to get it all setup and painted and turned out pretty good. I built it light enough to be able to remove whenever I wanted to take it off without it being a hassle. Now, while ATI does NOT recommend you putting the light into a canopy, this method has an open top and in your case open sides also. This will allow the fixture to not only breathe, but 100% reduce the light spill underneath the fixture.

 

[Moeshi]

I will most definitely look through your canopy thread! I've decided to give the 8 bulb fixture a shot. Now comes the bulb combination...

Thanks a lot, Hentz.