A different type of lighting question on MHs

[cookiemn]

I broke down and ordered a new 90 gallon tank and sold off my 4 month old 60 (thanks Colleen!!). Now I am thinking of upgrading the lighting to some MHs. I have read thru most of the links and decided on getting a dual 175 MH system with PCs or even T5s. I am looking at getting a hood versus a retro. I just don't trust myself that I won't get burned.

Here are the specs of the tank:

48x18x24
1/2 inch acrylic all around
euro top
coast to coast overflow with a center overflow box

How far should I suspend the MH hood over the tank so that I wont warp or damage the new tank? I have talked to a couple of stand designers and they have varying opinions. BTW, I was very impressed on how well Chris Crow thought out his canopy configuration. I just have to decide how tall the canopy is before I order my custom stand and canopy.

Erwin

 

[mattseattle]

why 175's and not 250's?

if i were you i'd go with 250's so in the future you won't have to upgrade. i had 175's on my 55 at first but then went with 250's due to my SPS and clams.

 

[wooddood]

i'll have to agree on the 250 watt bulbs, you tank is 48 long ans 24 deep you will need the 250 watters and supplement them with actinics, pc's or vho's your choice. i have a 120 48x24x24 and i'm running 2 250 watt 10k xm bulbs and four 03 actinic pc's and there just right. kinda like the three bears lol. good luck.

 

[cookiemn]

So dual 250s?

 

[mattseattle]

yup....and i have mine about 8" off the top of the tank. some say 12" but 8" was good for me.

i also have 2x110w 48" VHO's to supplement my MHs. 250's are not that much more expensive than 175's actually. It will definitely save you from upgrading down the road.

 

[cookiemn]

Well it looks like I am going to spend about 3 times the original amount that I spent on the 60 gallon set up.

 

[jesshimom]

For sure Erwin, and you just let me know when you upgrade that. I always love a bargain!

HAHA Colleen

 

[mattseattle]

buy a used PFO Dual 250w Ballast. That will save ya some money.

 

[cookiemn]

matt, your just daring to spend more aren't you.

 

[bc_slc]

I dont know if this helps or not but usually people recommend that MH's be 8-14" above the tank. If your eurobrace is in the middle, that is the best place for it. They are designed to not warp as much as if the whole top was covered. I personally would go with a bit more than 8" if you go with the 250s. I agree that the 250's is the way to go, but I would put them at like 10" at least. You will get a little bit more spread and it won't be quite as hot.

If you are custom making your canopy, I would try and leave some of it open i.e. the back or top - that will help w/ the heat as well.

Just some thoughts...

 

[bradreef]

250's will penetrate better and provide a lot more light. I have my canopy about 10 to 11 inches above the water.

 

[mattseattle]

spend more? i was actually trying to save you money! at least this time.

 

[Katchupoy]

I have a 175 and around 8 inches above water. My water heats up a little bit with blower on.

My option is to raise it to 12 inches. Temp were maintained, no considerable heat. No water splashes on my bulb. Light is still bright.

But, if ist 250 then it would be perfect. I can put it high enough but still maintaining more than enough light penetration.

 

[cookiemn]

The standard size for a MH canopy is about 12 inches. Talking to Chris Crow, he said I could make it as high as I want. I was thinking of 16-18 inches with the dual 250s. I was thinking of getting a retro dual 250s with two VHOs or PCs. The euro bracing is identical to the one that IAP had on the 90 gallon that they finished at the PSAS meeting so there is no brace in the middle.

Erwin

 

[mattseattle]

a retro kit to add to your canopy? those are expensive in my opinion. you could do a lot better...that is if you are trying to save money. if not then i'd say go for it.

 

[cookiemn]

Mat,
why do you say they are expensive? They sure look cheaper than getting a full hood set-up. If you know a cheaper place to get the setup then your holding out on us. Share that info Matt!

Colleen, I had dinner at Dang's place and saw his tank. My wife gave me the go ahead to sell the T5s at a loss and get some MHs. So I have a proposal. How about taking the T5s for $250 and letting me keep the skimmer and penguin pump that I is included in the tank, since you don't need them? I finally figured out that I need those two pieces for my 15 and 40 to keep my livestock alive while I wait for my 90.

 

[jesshimom]

Need another plan... Shilo is in desperate need of the skimmer.

 

[mattseattle]

I emailed you about the lights and stuff. Let me know if you didn't get it. Your PM box is full though.