Half inch out of level

[dizzy]

I'm setting up a 450-gallon Oceanic tank. It's 96" x 30" x 36" height. It's on a concrete floor and it must be .5" off level in 8'. Anyway I realize one side will drain more water than the other, but will being off that much stress the tank? It is pretty close to level front to back. It's on an Oceanic plywood stand, and it seems like shimming the low end would put a lot of stress on the shim area. What do y'all think, will it be alright to fill it up like it is.
Mitch

 

[Anonymous]

Wow, a half inch over 8' is a lot, IMHO. Where are you thinking of shimming? Directly under the tank, or on the floor under the stand?

 

[Eric P1]

If I were you I would level the section of floor befor setting up the tank. If the floor is bare concrete, you can skim coat the floor to level it. If you cannot do this you will need to find a way to securely shim the stand.

My .02 Eric...

 

[ReefMon]

My 180 was off by 1/2" on the 72" length and 1/4" on the 24" width on my carpeted concrete floor. What I did was to rip shims out of a 2x4 on a table saw that were 72" long, (plus and the matching 24" side shims). I glued and screwed these to a 72"x24" 3/4" plywood base and put this under the stand, so it is completely supported on all edges. Worked perfectly, totally level and solid as a rock for 3 years now.

HTH
Happy Reefing!
Glenn R

 

[npaden]

My floor had waves in it so that the center was high and both ends were low. I used about 3 packs of hardwood shims to get the stand to sit level. After filling the tank you need to double check it again. Mine ended up getting off level again when the rockwork on the stand was done but there wasn't any way to fix it at that point so it has been about 1/16" off level on a 10' tank for a couple years now. Really doesn't affect much but the left overflow does take on just a tiny bit more water than the right one. I would fix it if it was 1/2" though.

FWIW, Nathan

 

[EmilyB]

FWIW, I would shim.... 8O

 

[Anonymous]

My 180 was off by 1/2" on the 72" length and 1/4" on the 24" width on my carpeted concrete floor. What I did was to rip shims out of a 2x4 on a table saw that were 72" long, (plus and the matching 24" side shims). I glued and screwed these to a 72"x24" 3/4" plywood base and put this under the stand, so it is completely supported on all edges. Worked perfectly, totally level and solid as a rock for 3 years now.

HTH
Happy Reefing!
Glenn R

What you've described is exactly what I was thinking (except the ripping the shims yourself bit) as a possible best way to deal with this. I would think that as long as a softwood wasn't used it should be alright.. except for the post above regarding use of hardwood shims.

My worry with a skim coat of concrete is that I've seen it sometimes just flake off, but maybe it wouldn't if the weight were distributed evenly across it, instead of 4-6 points.

 

[Titan Trigger]

Hi,
You have asked the right question. I just had the same problem a year ago with my 200 gallon Oceanic. Theoratically, as long as the tank is flat on the stand, it should be fine. HOWEVER, that was what I thought when I set up mine on a carpeted floor until it eventually leaked and had to re-do the silicone. Trust me, you don't want that to happen on a 450 gallon.

Hopefully, you have not set it up yet and have time to put in shims. Again, as long as your floor is flat, the stand would hold the stress. it is more important for the tank to be leveled. It will never be completely leveled but with that size tank the least the better.

Although a lot of work, it is worth the effort. Now, I am enjoying my tank a lot more; I don' have to worry ALL the time how it is going to hold.

Best.
Titan Trigger

 

[dizzy]

Thanks for the replys. The floor is carpeted concrete so the embossing leveler is out. It is more difficult to shim under the solid plywood bottom than other types of stands. I had in in the back empty for awhile and just having it sitting on two flat 2x4s was causing it to bow down in the unsupported areas. I can imagine how an improper shim job would put an incredible amount of pressure on the high spots when the tank is full. The tank is difficult to level because it has Euro bracing and the glass strips were not all siliconed down perfectly flat with each other. It weighs something like 1000# empty too which doesn't make things any easier.
Mitch

 

[npaden]

Shimming it is the only way to go. Shim it until it is level then you can put in additional shims in to even out the pressure. My shims are 1" apart at the most and most of them are side by side with no space at all. That should even out your pressure. The pressure should be on the perimeter of the stand where the shims will be anyway. There shouldn't be hardly any pressure on the middle area of the stand where the solid plywood is.

FWIW, Nathan

 

[Anonymous]

A few thoughts:

As the others have suggested, I would shim below the stand. I was able to do this (~1/4") on an Oceanic 200 that was sitting on a hardwood floor while the tank was still 1/2 filled. I did this by inserting a whole lot of wood shims all around the base of the stand and pounding each shim in just a little at a time. If the tank is still empty, then this is a whole lot easier to do.

As an aside, have you talked with Oceanic? I have discussed similar issues with thme in the past and have found them to be helpful. I would be curious to hear what impact being out of level (but still flat) has on the strength of the tank. The claim that an out of level tank may lead to leaks and/or failures may be nothing more than a myth.

You mentioned that Oceanic made the stand for you and that it is plywood. The Oceanic wood stand that came with my 200 was pretty well built, but the Oceanic wood stand that came with my 175 bowfront does not inspire great confidence. The stand for my 400 is built out of tubular steel and sheathed with plywood.

After seeing how solid/rigid my steel stand is, I would hesistate to use a non-steal stand for anything as big as a 450. In any event, I would scrutinize the stand for your 450 and make sure that it is adequate. One big problem that I have with all wood stands, particularly when made from MDF or particle board, is that they can lose strength if soaked with water - a possibility that is impossible to avoid. I would make sure that the bottom 3-4 inches of the stand is sealed and absolutely waterproof. You may even want to coat the inside with firberglass.

And if the stnad does not have a lip all the way around the bottom to keep water from spilling onto the floor, then I would add one. Of course, by making the bottom of the stand into a bath tub, you do create the problem of shorting out you pumps or any other electrical equipment. But you can avoid this problem by elevating the pumps on pads. A well designed stand should be able to contain 5-10 gallons of water without allowing the water to contact electrical equipment.

 

[dizzy]

Well I was able to shim the left end and level the tank. We had built on to the store a while ago and they did a less than perfect job tying the two concrete slabs together. I was able to screw a 2x4 on the left end plywood and lift the tank and stand with a tractor jack, while the shims were inserted. The tank is about half full, but since the water is so cold I think I will fill it slowly. I'm going to be using a 75-gallon tank for the sump and it is directly behind the tank on the other side of the wall. I used a 3" pipe as a trough. The tank has 1.5" bulkhead fittings at each end. I simply drilled 1.75" hole in the top of the 3" pipe and ran flexible 1.5" PVC from the bulk heads to the trough and sealed it with plumbers expoxy. The 3" tees through the wall and to the sump. The sump is in the employee bathroom now. I ran the return lines in 1" pipe and reduced it at the bottom of the return bulkheads which were 3/4".

The tank is naked now, but it will look much better (hopefully) when I get it trimmed out. I was hoping one of the engineers out there would weigh in and tell us how much more pressure is exerted on the left end glass if it is .5" lower than the right side, compared to being set up level.

I attached a picture of the tank on the Oceanic stand, and one of the sump as well. Everything is bare bones right now, but I want to circulate the water and check for drips before I complete the filtration and put the cosmetic touches on the tank and stand. Thanks for the replys.

 

[Anonymous]

Make sure you make a cover for the sump. It would really suck for a drunk party gower ti think it was a urniral.

 

[Anonymous]

The stand looks pretty beefy. Still, a piece of plywood fastened to the front of the stand at each end or in the middle would provide additional cross-bracing and insurance from torquing/collapsing of the stnad.

Since your sump is not inside the stand, many of my previous comments don't apply.

 

[dizzy]

Make sure you make a cover for the sump. It would really suck for a drunk party gower ti think it was a urniral.

We run the drunks out of the store. :wink: Actually we have a couple of bathrooms and that one is going to be remodeled. It just happened to be behind the perfect spot to set the tank up.

 

[REEFKEEPA]

The pictures look good. If the stand is close to level now you should be fine. Have you run power to the location yet?

 

[dizzy]

The pictures look good. If the stand is close to level now you should be fine. Have you run power to the location yet?

Sort of. I ran conduit and set a 4x4 box above the tank. I have a dedicated circuit for this tank. (Can easily pull another as well for lighting.) I put a cut-in box on the side of the wall the tank is on. Then I decided to put the sump on the other side of wall where it would be more accessible, so the receptacle is on the wrong side of the wall. Anyway the tank is full and water is roaring through the pipes. No leaks, no drips, no errors. FYI water started to drain down both overflows at precisely the same moment, so I'd say it is pretty level.