Low iron glass

[Delphinus]

Well, it's a judgment call. Personally, I think, if it's a reef tank, you might as well go for it, so long as you can afford it. If it makes the difference between having a tank and not having a tank, then don't sweat it. But otherwise, I highly doubt you'll find yourself, down the road, assuming you did get low-iron, saying something like "Darn, this tank's glass is entirely too clear, what a waste of money."

If you're looking at 1/2" glass, you can totally tell a difference between regular and low-iron. Regular looks green in comparison.

On a (comparisonly) low lit tank like a FO, it's probably overkill. But on a brightly lit tank, it might be worthwhile. I think you can tell a difference between low-iron and not-low-iron glass on a reef tank.