Crystal glass/low iron glass has higher clarity and has a light blue tinge compared to the green tinge of normal glass.

For aquariums with thicker glass, (8mm or more), the difference in clarity is significant and worth the investment.

For small tanks (10 gallon and below) with thinner glass, the effect is less noticeable.
​Crystal glass will often cost significantly more. However, the clean lines and clarity of rimless crystal glass tanks greatly increases the aesthetic appeal of aquascapes.