I personally don't think it would be worth building one, esp. for a set up that big. You're just going to have to come to terms that with a bigger tank, you are going to have bigger expenses. I wouldn't even consider a home built skimmer on any tank...even on my 20 gallon. If they were that successful then you would be seeing lots of posts about them....and the fact that you can't find much information should be the first red flag that it's not worth it. Don't rush your tank and just invest in a quality skimmer that is rated for more than what you have... Mine and Chris's skimmer is rated for 300 gallons...and that sucker pulls out a lot