Not really Panoid about it Pete like you said before i already have that much water down there, i trust your judgement more than most people on here hah.. I've heard of drilling holes and filling with concrete pilings, i'd def do that myself before i called someone to take a sample and tell me im crazy for the amount of water in my house already.I think I've decieded on 8'x12' for the sake of space for humans in my home hah... The difference of 2 ft. seems nominal in the footprint for the fish. and theres room for a couch in front of my viewing window if i stick with coming 8ft. off the wall. Who knows, you know as well as i do things change during the actual builds. I have a feeling my better half will kill me or move out if its 10'x14' (assuming she'd ever take a tape out lol) My lengths of 2"x3/16" box steel are 10' and its killing me to cut them down so we'll see what happens. Started the thread for a bit of reassurance and youve given me that. Thanks. I'll start posting pics soon of this build and some old ones of my 650. No ones built a tank like it and alot of people told me it would never work in the original thread. My new design is basically the same thing but improved and cheaper. Funny thing is the cost for the 2700+ will b around the same as the 650 was. a good note for anyone else debating about tank size. 650 is a nice grow out tank but past that nothing spectacular.If you're really paranoid about it. Have someone come in and drill in 6" holes i your slab, then dig them out a foot or so and pour in concrete pilings. I don't think you need it though. I added about 4-5" to my garage slab to raise the floor to the same as the rest of the house. I did that before I planned my tank when the room was going to be a workout room before it became my fish room. I regret not putting a floor drain in. Doh! It wasn't supposed to be a fish room when I did that.