[vbsaltydog]

I have a 54g corner bowfront that is 21" from the sandbed to the waterline. I have an orbit 30" PC 2x65 but I want to start keeping corals so I decided to upgrade. I have read that T5's are great and I don't disagree but I want the shimmer of MH. I am considering a MH/T5 combo and am down to one last factor. Do I get the 150w HQI or the 250w HQI? Either one will be supplemented with 2x24w T5 actinics.

Is the 250w HQI too much light for a 54g corner bowfront?

[wonderboy]

Nah dude! Ive had 800 watts over a 55g before, corals did amazing for a few months, then I got a bigger tank. So have at it! Your corals will love you! Just start um out low and acclimate um to the top.

[vbsaltydog]

Great. I was hoping that would be the case. I like the bright shimmering of the MH 10k even though the 14k is supposed to promote growth better. I wanted some "deep water" blue effect but didnt want to sacrifice the bright shimmer of the 10k so the 10k HQI with the T5 actincs seemed to be a great solution. I didn't want to get the 150w only to find out that it was underpowered but I also didn't want to get the 250w and then "melt" whatever I put in the tank.

Any other advise is welcome.

[pogodzib]

If you're only going to add 1 MH over the tank, I'd go with 250w MH, but if you are going to have 2 MH bulbs, I would stick with the 150w MH bulbs.

[vbsaltydog]

Originally Posted by pogodzib

If you're only going to add 1 MH over the tank, I'd go with 250w MH, but if you are going to have 2 MH bulbs, I would stick with the 150w MH bulbs.

Its a 54g corner bowfront so the dimensions of the top dont allow anything wider than 30" and there aren't any dual MH combos under 30" so I have to go with a single MH plus they say that a MH is supposed to cover a 2' x 2' area and that's perfect for my tank since it is a corner bowfront design.

My only concern was .... is 250w of MH going to melt any of the corals assuming that I keep the softies near the bottom and out of the most intensely lit areas?

[pogodzib]

I was thinking that the width would allow for a 36" fixture, of which some of them have 1 MH bulb and others have 2 bulbs. As for too much light for the corals, you don't need to worry about it once they get adjusted to the light. I have some soft corals near the very top of my tank under 250w MH + 2-VHO bulbs and they are just fine. During the initial acclimation to the new light, either use 2-3 layers of screen to filter the light or keep the coral low in the tank and gradually raise them/ remove the screen over a two week+ time frame. My only concern with the 250w bulb would be heat, but their are plenty of ways to deal with heat besides a chiller if the heat does become a problem.

[vbsaltydog]

Originally Posted by pogodzib

I was thinking that the width would allow for a 36" fixture, of which some of them have 1 MH bulb and others have 2 bulbs. As for too much light for the corals, you don't need to worry about it once they get adjusted to the light. I have some soft corals near the very top of my tank under 250w MH + 2-VHO bulbs and they are just fine. During the initial acclimation to the new light, either use 2-3 layers of screen to filter the light or keep the coral low in the tank and gradually raise them/ remove the screen over a two week+ time frame. My only concern with the 250w bulb would be heat, but their are plenty of ways to deal with heat besides a chiller if the heat does become a problem.

Can you briefly provide a list of ways to deal with the heat, other than a chiller?

Is it fair to say that keeping the house A/C on approx. 75 degrees coupled with the fans in the light fixture should keep the MH heat from becoming an issue?

I plan to keep the fixture a good 4" above the water line too.

[jimw369]

Originally Posted by vbsaltydog

Can you briefly provide a list of ways to deal with the heat, other than a chiller?

Is it fair to say that keeping the house A/C on approx. 75 degrees coupled with the fans in the light fixture should keep the MH heat from becoming an issue?

I plan to keep the fixture a good 4" above the water line too.

4" is pretty close to the water for MH. T5s yes. MH probably not.

Heres my list (seeking Pogodzibs approval of course):

move tank to room where no sunlight comes in
Raise light fixture
put tank in basement
fan blowing across top of tank
fans in hood
Fan on sump
Add more fans and in case of fan failure...float frozen 2 liter bottles of water in sump(emergency measure only)
Make your own chiller from an old refrigerator(some have done this I have not)

[pogodzib]

Originally Posted by jimw369

4" is pretty close to the water for MH. T5s yes. MH probably not.

Heres my list (seeking Pogodzibs approval of course):

move tank to room where no sunlight comes in
Raise light fixture
put tank in basement
fan blowing across top of tank
fans in hood
Fan on sump
Add more fans and in case of fan failure...float frozen 2 liter bottles of water in sump(emergency measure only)
Make your own chiller from an old refrigerator(some have done this I have not)

My MH are about 4" off the water, which is fine as long as the bulbs are enclosed within a fixture. If the bulbs are open to the water, 8" is a much better distance.

I agree with Jim's suggestions for keeping a tank cool, plus:

Lowering the temp in the room with the tank via an air conditioner
Shortening the MH light cycle (4 hours is plenty for corals)
Running your RO unit's feed water supply line through coiled tubing in your sump
Run your tank water through a large, trashcan filled with your fresh makeup water (assuming that your home's temp is the same or lower than your tank water)

And yes, if your house's temp is at 75 degrees, fans should be enough to keep your tank water temp down with that lighting.

[vbsaltydog]

Thanks pogo