I can see your point with the stability, and thankful that you made it. I don't think I'll be able to move that fish tank unless I put wheels on it...even though it won't ever be filled up to the 100 gallon point, even at 80 gallons it's still gonna be roughly 640lbs + whatever the tub itself is gonna weigh. I offset the grow beds on the boards to kind of counter attack that sag issue and give a good amount of the weight to the posts themselves. David said he used the same tubs and with the media they were close to 230lbs. All good points and I'm not expert in engineering so thank you for those tips.