[meandean45]

Hi Frauleinmm !

The size of the tank depends as much on money, space, willingness to work on it and what you want to keep in it as anything else. The common wisdom used to be that you didn't start a reef smaller than 55 gallons, but an awful lot of people start a Nano reef and suceed with as little as 10 gallons.

I guess that the first question would be "Do you have room for a large tank"? I you have room for a 55 (4 feet of wall space) then you most likely have room for a 90 or 120 (still 4 feet long, just taller and deeper). If you have 6 feet of available space, a 125, 180, or 240 will fit in that space, and If you don't live on a tight budget, I'd recommend getting the biggest tank that you can afford, even if it means that you might have to wait awhile to save up for the bigger tank and equipment that it needs. The more water volume that you have, the easier it is to keep the water quality balanced, and more importantly (to me) the more room you have in your' tank, the better.

When you first set-up a big tank, it looks awful empty, but as things grow you find yourself trying to make room for just the things that you have, much less new aquisitions. Once you get a big tank set-up, it's a major undertaking to move/replace it. You can't just pick up a 90 and move it aside while a new 180 cycles to replace it!

As far as the Glass/Acrylic thing goes, I've always had glass, so can't really give you a good opinion. My Acrylic sump has been great, but then all a sump need do is contain water and equipment. Some that I know will swear by acrylic, others glass. The lighter weight of a truly large acrylic tank seems to make sense, until you consider that 240 gallons of salt water at 8 lbs. per gallon + or -, weighs 1920 lbs. al by itself. If your floor will hold that much weight plus the acrylic tank, most likely it will hold the glass tank as well.
Hope that this will help.

Regards,
Dean