So I'm in the process of ordrering the supplies to do this to my fixture. But I need to know the dimensions of this ballast before I order. Does anyone know the dimensions. J&L is too busy to look for me.

http://www.jlaquatics.com/product/sl...t+Ballast.html

I don't know the dimensions, but the photo makes it look large. If they are big, they won't fit in the hood... There isn't that much room in there.

Have fun, post pic's of the process.

Personally I loved my Coralife, but found the Hamilton Belize sun in the 5ft which is the length I wanted. I have only had it a few weeks, but love it. Top notch construction, MH with T5HO and LED's. This may be something to look at, talk to Jeff at JL, as he can order it. You will be suprised by the reasonable price including shipping and GST.

Thanks. I found everything I need for $130 taxes in but no bulbs. But at LFS they want $56.79 per bulb. At J&L I can get the bulbs for $13.48 per bulb. The ballasts I found here are going to fit in my fixture but this one that I asked the dimensions for will be alot cheaper. Usually there is no returns on electronics so I'm holding off on ordering the lights until I get the dimensions.

Another question... will I even notice much of a difference if I change out my 2 96w PC's for 4 54w T5's? The PC's are only 30" long and the T5's are 47" long? I will be only using them for actinics. If not too much of a difference I wont bother. Stupid questions I know, but I don't know anyone running T5's to compare against. I run Giesemann 250W 13000k for my MH

I believe you will if they are High Output T5's, regular T5, NO...

I can say my new fixture is T5HO, and I see a difference compared to the PC

Thanks Mseepman! Your mod was really helpful and made me finally decide to do this. My fixture is a 48" and my PC's were only 34" so I gained a good amount.
http://i255.photobucket.com/albums/h...T5bulbs002.jpg

So I got 2 of these ballasts and 8 eight end caps from Nedco.$131
http://i255.photobucket.com/albums/h...T5bulbs003.jpg

These are the ballasts I removed. I found burned marrett and replaced them as well with better ones.
http://i255.photobucket.com/albums/h...T5bulbs001.jpghttp://i255.photobucket.com/albums/h...T5bulbs004.jpg
I thought I could slip these ballasts over the reflector for the MH but they are a little too fat. So I screwed them on to the back of the fixture and they are only visible from the back of the tank anyways.
http://i255.photobucket.com/albums/h...T5bulbs005.jpg
I just removed the clips for the PC's and screwed the capends to the reflector.
Here they are on.
http://i255.photobucket.com/albums/h...be/May7015.jpg

Here's my tank with only the 4 54w T5's turned on. I got the cheap Coralife Actinic bulbs from J&L for $13.88 each. With shipping it was about $80. I'm sure I could have done it for cheaper yet so I'm happy for $210
http://i255.photobucket.com/albums/h...emay7005-1.jpg