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#### Anonymous

##### Guest
I read here, a few days ago, a post conserning tank weight and the strees it does on buidings if kept on 2nd floors and so on. I have a 75 gal on a floor with a basement below it. Do I need to be concerned with this? Also thinking of putting a bigger tank in the finished basement. The basement has a 6 in sub-floor.....would this be a problem?

Thanks
PeteS

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#### Anonymous

##### Guest
Hey Pete,

While tanks can weigh a lot, the weight is usually evenly dispersed over a large area on the floor. I remember a fellow reefer on one of these boards figured out that a human standing actually puts more pound per square inch of pressure on the floor than a tank does. This, of course, only works if your tank has a flat bottom. I think the formula is pretty simple: calculate the total weight of the tank and then divide that by the total square inches of the bottom of the tank which come in contact with the floor. As for your 75 gallon, it should be fine on a second floor.

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E >< () !) !_! S

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#### Anonymous

##### Guest
PeteS,

A 75-gallon should not pose a problem if you keep the following in mind.

#1 Place the tank against a wall where the floor support beams are resting on their supports.

#2 Place the tank perpendicular to the floor support beams as opposed to parallel.
The concrete slab in you basement will have no trouble support virtually any sized tank.

Regards,

Scott

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#### Anonymous

##### Guest
srbayless,

The basement has a approx. 6" sub floor. Will the wood construction of the sub floor handles the weight. Also, it is level from front to back where I want to place the tank but from left to right, if i were to have the tank level the left side would have a 1'2 inch gap under it. Hope that doesnt confuse you. Also, the numbers are approx. I'm no surveyor.
PeteS

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#### Anonymous

##### Guest
Hi PeteS,

Sorry for the confusion, I thought your basement floor was concrete. Since it is wood, how much weight it can handle depends on several things.

1. How is the subfloor attached to the foundation?

2. What kind of beams are used for the subfloor? dimensional 2x6" or I-beams?

3. Are there supports holding up the subflorr between the foundation?

If you have a very well built subfloor, it should be able to handle a 150-200 gallon tank. If the subfloor is not very sturdy, it should be able to hand upto a 100 gallon tank.

Good luck!

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#### Anonymous

##### Guest
As someone who knows a bit about construction, I'd like it interject some information. A tank on a concrete basement slab poses no structural threat at all. the above posts are correct in that the tank MUST be level. As far as a tank on a wooden subfloor: 2x6's are not used as floor joists. 2x8 is the minimum and it is mor likely to be 2x10 which will likely be 16" on center. Above these joists is the subfloor material, which is likely 3/4" tongue & groove plywood, which ties all the joists together and makes a "system", so it doesnot matter if the 4' dimension of the tank is parallel or perpendicular to the joists. If the tank is located above a bearing wall or a support beam (one that holds the joists up)you will notice much less deflection in the floor than if ti is in the center of the span. Most residential floors are designed to support a live load of 40#/sq. ft.over the entire floor, with a deflection of 1/360 th of the length of the span of the joist. A 12' span will deflect 1/30th of an inch. Think about having a party and having 6 guys playing poker at a table. That is about the same weight situation you are dealing with. As we said when we went West "Damn the mules...Load the wagon" Good luck.

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#### Anonymous

##### Guest
Hi PeteS,

A 75 gallon tank won't be a problem as long as you place it next to a wall, preferable a load-bearing one. I think I recall the post you are referencing. The person wanted to put a 150 or 200 gallon tank on the 2nd floor of an apartment building. At an average of 10 pounds per gallon, the tank would have weighed a ton. Even over 12 square feet of stand (6' x 2'), the floor would bow at the very least and very likely collapse.

Your basement will be able to handle any tank you put on it, just make sure the tank is level. Most basement floors are slightly sloped to facilitate water flow into a sump drain.

Good luck.

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#### Anonymous

##### Guest
Pat Y,

I beg to differ. I have personal experience with a 135 gallon tank cracking a 2x10 joist that it was directly above. This was on a floor that was constructed of a ¾” subfloor covered by ¾” oak hardwood. Whether the floor is “unitized” on not, It is still being supported by the joist.

By placing a tank perpendicular to the joists, you spread the load over as many joists as the tank stand is above. When you place a tank parallel to the joists, you are placing almost the entire load on 1 or 2 joists.

If you place the tank in the middle of the room, away from a load barring wall or footing, parallel to the joists, you have the least load barring capacity.

Regards,

Scott

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#### Anonymous

##### Guest
While I agree with most of the posts here, I added a supplementary support underneath my 90 gallon tank. It cost me less than \$10 to get 2 2x4's, nail them together, and then cut them to just fit between the concrete basement floor and the bottom of a floor joist directly under the tank.

FWIW, anyone with a really old home should consider this (IMO). While my home was built in 1909, that's not old enough to worry me. The supports are bigger than in modern housing. But much older homes could have just about anything for floor supports.

Maybe you guys that live out west don't have many of these around, but we've got plenty of homes around here from the 1700's, and the floors move in some of them as you walk around <G>.

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Randy Holmes-Farley

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#### Anonymous

##### Guest
Randy,

Great Idea!

The original portion of my house has a full basement, but the room that my new 200-gallon tank is going into was an addition that was built over a crawl space with a concrete slab. I can add 3’ 2x10 supports between the slab and the joists. (2 per joist) I need to get into the crawl space to do my drain/fill tank plumbing anyway.

Thanks,

Scott

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#### Anonymous

##### Guest
I recently (2 years ago) installed a 180 gal in a brand new home, perpendicular to the floor joists (2x10's). I wasn't too worried about the floor cracking or breaking, but of the deflection and subsequent splitting of the tank seams. To prevent this as much as possible, I installed a 2x4 stud wall beneath the tank, across the joists and in parallel with the tank. I shimmed the wall tight prior to filling the tank to ensure a very snug fit. It seems to be working well, and I sleep better at night.

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My reef is a living creature, it is not an object that I own.