it depends on how old the house is. By my quick calc's you are looking at putting 90psf on a floor that is usually designed for around 40-50psf.

Now, if your span is less than 10' and you are fairly close to supports (beams) you might be good.

An engineer would be your best bet to confirm what you can do, it should only be a couple bills to have one look into it.

BTW, you might never have a problem, I have seen waterbeds over 2x8 joists.

A larger tank might work, you just have to see what the final loading will be. If you can get things to under 75psf I wouldn't worry about it.

I think a little caution in general here is a good thing. Your party leaves sometime that night/early morning. Your bath sits on a floor that is built differently than the rest of the house.

I'm not at all concerned about it going through a floor. I don't like my reef to wobble or bounce is all. And long-term, the effects on the floor are measurable. I've read a lot of large tank threads over the years and yeah no one has put a tank through the floor but some have actually measured the floor sag. I didn't want my floor to sag either.

See the tank won't be held up by 4-6 joist, but parrellel with 2 of them. Thats my problem. If the joists were running the other way on the house i would have no concern, but i have never seen someone run a tank or confirm it will be ok for 100-120gal tank. Otherwise Like i said i will just re-design a 60gal and work with that since i know people are running 55gals without any issues.

Here are some pictures of what i am dealing with.

i want the tank placed where the black couch is
http://i37.photobucket.com/albums/e6...0/DSCN6538.jpg

my "joists" which are about 2 feet apart
http://i37.photobucket.com/albums/e6...0/DSCN6540.jpg

Another idea of what the joist looks like
http://i37.photobucket.com/albums/e6...0/DSCN6541.jpg

^^ damn, never saw those cross beams in between when I looked.. haha

Those TGI joists also calle silent floors are extremely strong think of your wifey saying she weighs 130 pounds not very big she walks around the hous in heels ..... Every step all 135 pounds goes onto the heel which is say 1/2 diameter that's 270 psi on the plywood floor..... She doesn't fall through

but she doesn't stand in the same spot for 365 days of the year :lol: Or does she? :noidea:

yes yes I know it won't make a huge difference either way, but in principle I think 1000+ pounds in the same spot over the course of 365 days or more will eventually make a difference. But I'm not a builder so what do I know.

So in other words... I shouldn't have anything to worry about?

that's pretty much the general consensus that I got out of my thread and now yours as well :-)

Just hurry up so I can buy your old tank.. since Josh won't sell me his. :lol:

Sweet, well i guess its a go than. I'm probably going to start on the stand in 2 weeks.

lol its going to be a couple months before the tank goes up for sale. Need to get everything together for this one.

If I were you I'd have posted asking about a 300 gallon. Then people would have said 150 was safer and we'd all feel great lol.

Build ON!