125 gallon tank stand question.

everpresentnoob · Jul 7, 2026

So I just acquired a pretty good price 125 gallon tank and stand. I'm planning on putting baffles in my spare 40 breeder to use for a sump under it, but the stand with the center support in it is 1 in too narrow for the 40 breeder to go into it. I'm thinking to center the sump under the tank and then have two supports on the front on either end of it so I can access all the equipment in the entire sump. But I am wondering if 36 in is too long as span for a 2x4 to be unsupported in the center of this thing. Or I could push the sump to one side of the stand and have a center support that is around 1 inch off the center. There will be a 2x4 across the top to support the tank, and then the frame on top that you see will be on top of that with the tank resting on that frame. I like the aesthetics of the center mounted some, and that would actually give me two supports in the front of the stand. Looking at my wife's 125 tank and stand it only has a single center support so maybe I'm just overthinking this.

I could also do a little reconfiguring and use a 2x6.

Thoughts anybody? #Rocketengineer ?

Gumbies R Us · Jul 8, 2026

@Troylee

everpresentnoob · Jul 8, 2026

I was just thinking, If I put the sump in the center of the stand, then I can wall off one side for electronics and put my ATO res on the other side. Perhaps thats the best way to go about this as long as I can get enough support across the top.

fishface NJ · Jul 8, 2026

everpresentnoob said:
I was just thinking, If I put the sump in the center of the stand, then I can wall off one side for electronics and put my ATO res on the other side. Perhaps thats the best way to go about this as long as I can get enough support across the top.

I would do that.

Fish Fan · Jul 8, 2026

I think you're fine to place the sump tank in the center, and two vertical support stiles on each side of the sump tank, link in the second photo above

You can check out Rocket Engineer's calculations for when to use 2x4's or 2x6's etc. at this link:
https://www.reef2reef.com/threads/basic-diy-stand-calculator.1138386/
From the above link, RE recommends using 2x4's for 48" of horizontal space, for tanks up to about 75-90 gallons. You have a 125, but it will be supported by two vertical 2x4 stiles , and the spacing will never be more than 36" between the verticals, so I think that should be fine.

I built a DIY 2x4 stand for a 125 some years ago, and I had just one stile support in the center, so 36" to each side of the center support, and that was just fine

@BeanAnimal

Good luck!