Ahh Glass... clearly a tinted subject.
The Reef folks have addressed this already. The Reef Central forums have extensive conversations on the optical quality of many forms of glass. I looked into have a custom tank contructed and learned quite a bit about glass.
AGA, Perfecto, Oceanic and probably others use standard LOF Float glass. It's pretty much the same glass that the windows in your house are constructed with the difference being the thickness. Windows are typically 1/32" and the green tint is not noticed unless you look at the edge of the glass. When one moves to the 1/4" or thicker glass used in aquarium construction the tint becomes noticable. This is not a quality control issue, this is construction to a price point.
Below was orginally posted on a different forum by me
Learning about Glass
In researching builders for a custom sized tank, I learned a bit about glass. My experiences
LOF : LOF = Libby Owens Ford, one of the largest plate glass manufacturers in the US.
Float Glass: Float Glass is a term for perfectly flat, clear glass (basic product). The term "float" glass derives from the production method, introduced in the UK by Sir Alastair Pilkington in the late 1950's, by which 90% of today's flat glass is manufactured.
There are various grades and trade names for Float Glass. For my purposes I am mostly interested in optically clear glass, generically known as Low Iron Glass.
Low Iron Glass Types
Optiwhite: Practically colorless, Optiwhite™ Low Iron Float Glass virtually eliminates the green cast inherent in standard clear float glass and particularly noticeable in thicker glasses. Its colorlessness is especially apparent when combined with white or light colors, and when exposed, polished edges are in view. Ideal for applications where enhanced clarity and aesthetics are desired, including photovoltaic modules and solar collectors, showroom and furniture applications such as tabletops, and for use with ceramic decorations. Pilkington Optiwhite™ Low Iron Float Glass may also be used in architectural applications.
Diamante: As above by AFGS Inc.
Starphire: PPG (Pittsburgh Plate Glass) product optically similar to both the above products. Also available with blue edge, mostly used in doors so people can see the edges. See http://www.ppg.com/gls_commercial/starphire/default.htm
for optical differences between Low Iron and standard glass.
Optically the above 3 are pretty much interchangeable. Allegedly Starphire is the clearest of the 3 and is the most widely distributed. Pricing is slightly higher then Diamante and Optiwhite.
All 3 are available in various thicknesses, for my proposes 12mm is sufficient for the vertical surfaces. Vertical spans greater than 72x30 require, thicker glass and/or cross bracing. To archive greater thickness lamination is required, significantly increasing the price and complexity.
Optical clarity for the base and back of the tank are a non-issue to me. Standard 15mm float glass is sufficient for the base, 12mm for the back panel.
In aquarium construction there are two basic bracing methods; cross and Euro/perimeter.
Cross bracing are panels of glass attached at the top spanning front to rear. Depending on height, glass thickness and width of opening these are generally installed every 2’, minimum of 3” wide. These are a non issue for a closed top aquarium with standard florescent lighting. Care must be used with Metal Halide type lights as the heat generated can crack the brace leading to catastrophic failure. See http://www.glasscages.com/?sAction=V...amp;lPictID=65
for an example of cross bracing.
Euro or perimeter bracing are strips of glass attached parallel to the bottom pane, overlapping at the corners. Depending on design, these start at 2”. See the above example, mentally remove the cross braces. The advantage is the tank is truly open topped and since I will be using Metal Halide lighting I will have no worries of failure from the cross brace.
There is a dearth of info regarding experiences with various venders in FW forums, the reef folks, however, have some extensive conversations about the entire process, from design to delivery.
Warning, These are MY opinions gleaned from various readings, conversations and web site visits.
In alpha order.
Aquarium Obsessed. http://www.aquariumobsessed.com/
Based in Toronto. All calls and emails have been returned in a reasonable amount of time. Reported to be obsessed with creating a perfect product. All edges are both ground and polished reducing the possibility of chips. Medium high price. Long lead time.
Based in TN. All calls and emails have been returned in a reasonable amount of time. Does not build with anything but float glass, no options for Starphire or others. Reports are that seals are messy and that problems are not easily resolved. More delivery options then others. Short lead time. Low price
Based in Calgary. Initial calls and emails promptly addressed however I have read many reports of increasing difficulty in dealing with this company expecially with delivery times and pricing. Low price for Starphire, however reports are that while advertising Starphire in reality uses Optiwhite. Low price, inconsistent lead times, many other reported issues.
Leemar. Website under construction for over a year. Very few reports on company, not pursuing due to exorbitant shipping costs from California.
Based in Dallas, a division of Perfecto, who I believe was bought out by large garden supply company, I could be wrong there. Excellent quality, medium lead times, VERY expensive. (Edit, Oceanic is now part of All Glass Aquarium)
Disclaimer, The above is purely MY OWN opinion.