[randymon]

I will be putting in my new 125 gal in a week or 2 and the tank unfortunatley will be sitting on 2 floor joists running parallel, but the the house was built in 57 and has 2 by 8 tongue and groove subflooring so am I ok with weight or not?

[GaryZ]

Originally Posted by randymon

I will be putting in my new 125 gal in a week or 2 and the tank unfortunatley will be sitting on 2 floor joists running parallel, but the the house was built in 57 and has 2 by 8 tongue and groove subflooring so am I ok with weight or not?

Thats a tough one. If your guaranteed to be sitting on 2 joists you might be ok, depending on the size of lumber used for the joists and what the span of the joists are. The goal is to transfer the load of the tank right down to the footings. The 2X8's on the flat will help spread the load to other joists. But if your floor joists are 2X6 with a long span, say 10-12', I wouldn't risk it. 2X8 and bigger would be ok. You will also need to inspect the entire length of each joist in question for any signs of rot, pay special attention to the portion of the joist that actually sits on the foundation.

One question, whats under the floor? Basement? Crawlspace?

If it were me, I would go the extra mile and install some bridging between the two joists and shore it up to whatever is underneath, just to be safe. Especially if you plan on keeping any more water volume under the tank (refugium or sump or both).