Just make sure the weight is supported by the vertical 2x4's, not "hanging" on the screws. I always build my stands to hold triple the weight, at least, so I've never had an issue!
It depends on the size of your tank. Realistically, 2x4s can hold hundreds of gallons if you build it right. Even more realistically, people will use larger boards and double everything instead of stronger design.
Both work just fine.
For anything less than 250 gallons, I would say don't stress about 2x4s.
Go with lag screws and aim for at least 1.5" of penetration into the secondary wood. (2"+ is best, but I'd say 1.5" penetration minimum- I've got them going 2" and 2.5" in the stand I made for my 38.)
Go with lag screws and aim for at least 1.5" of penetration into the secondary wood. (2"+ is best, but I'd say 1.5" penetration minimum- I've got them going 2" and 2.5" in the stand I made for my 38.)
I agree. I wouldn't think about using anything larger than 2x4s unless I was building a stand that was probably 500+ gallons. 2x4s are stonger than most give credit for. It is all about design.