As you've said, there is no simple answer. My rule of thumb is that any tank
over 75 gal. gets a floor jack put under it. They only cost about $20, and
thats pretty cheap insurance. After the tank has been set up for a year or
so, I check the jacks to see if tehy're supporting any weight. If they're
not, I take them out. BTW - I set the floor jack up with just enough
pressure to keep it from falling over if it gets a light bump. That keeps me
from lifting the house off its foundation, and makes it easier to check the
jacks to see if the floor is settling....

good luck
--JD


"Sunshyn" wrote in message
. net...
Obviously the answer to this question will vary depending on the house
but..... at what point do you all think that a tank is heavy enough to
require added support to the floor (ie: bracing the floor from the
basement?)