Agree with Caryl.
I would not use it on a big tank either. In fact I would never use an UGF for any tank. I'm not saying they are bad but there are so many other, in my view, more practical and efficient ways of filtration nowadays. For that size tank I would use a good sized external canister filter.
There are so many uncertainties with UGF's. How much flow will there actually be through the substrate? and how much bacteria will any given substrate support? who knows... and if you want the substrate layer deeper in some areas then the water will flow through the least resistance i.e. the shallower areas and that may reduced the filtering capacity but again who really knows..
They certainly had their day but I think their time on this earth is over, or should be (many will disagree with this)
If you are keen on an in-tank air driven system you could look at doing a HMF (Hamburg Matten Filter) which in my view is a much better and easier system than a UGF.