Leveling a Tank
 

I never leveled my 10 or 12 gallons. I've got my new-to-me 33 gallon to within an 1/8" (36x12x18, with a crossbar at the top). I'm thinking my 40b (36x18x14) will have to be bang on.

What is an acceptable margin of error?

After having a tank break on me... I level to within a 1/2mm using a surveryers scope

Any idea how much you were out on the tank that broke? What size tank was it?

The level is a great idea. I'm a cartographer in a legal land survey firm, and I have surveying field experience. It never occurred to me to grab equipment from work for this job. *doh!*

An unlevel tank won't break from that alone, that's another issue. If you can run a 2" wave on a tank without concern why would 1/8" off level be a problem?

On that note why is it so hard to level a tank?

It was out by 1/8" from the shim compressing BUT the place that built the tank also used a peice of glass with a huge shell on the bottom which they shouldnt have which is were it cracked... So if the bottom wasnt a bad peice it may not have happened, but I take no chances.
I first level with a stanley fat max level to get it close, they claim there accurate to .5mm but I dont trust them that much

This is the first time I've ever leveled it a tank. It wasn't hard to get it to where it is now, but I would have needed hubby to produce different shims for me to get it more level. I don't know what kind of aggravation that would have involved.

I just used a Stanley Fat Max level.

As an aside . . . What is a "shell" as it relates to glass? That is a totally new term to me.

http://i79.photobucket.com/albums/j1...BLE-OYSTER.png
That is a "shell" in glass from some improper SSG

oh! That's ugly. :( is that your tank? My Google images search turned up nothing.

No thats not my tank, I have since fixed and sold that tank.
Thats just a pic to show what most shells look like and possible crack points on glass. It was from a SSG warranty job.

That's just bad tank building, being level wouldn't have helped.

I repeat thats not my tank its a example. And FYI ive seen hundreds of tanks with shells that havnt cracked. Its all about pressure and torque on that point

Yes which has nothing to due with the tank being level, if it's properly supported and the glass is ground flat or placed on the outside that type of failure won't happen even if you're out by an inch.

Out by a inch? If your tank is out by a inch it WILL break even if its perfectly made... Its just a matter of time...
Ive seen many broken tanks and even seen acrylic tanks that cracked being out of level

wrong, I can prove it with science.

If you're worried about it being closer to perfect, and for your 40b, I use the composite shims from home depot
These may be similar to what I used. Mine are man-made composite plastic and grey-ish
They don't crush like wood and are easy to score and snap

As for your leveling, my 125g was out 3/8" left to right and no worries for over a year
My 75g is perfect using the shims

Just keep in mind that you may want to re-level it after it's full and has settled for a day or 3

Im not wrong, Im a glazier I know how glass works and cracks when its torqued out of level.
But im not gonna continue to argue with you, thats not the point of this thread

How does one re-level a full tank?

I'll have a look for those shims.

I have always used plate steel for shims. Any metal shop can cut you some from scrapes.
When I leveled my 90g I filled it up 4" to level the water line cuz the plastic top might not be level right. I then shoved a small pry bar under it and lifted and slide the steel under. Filled it half way and checked again. Filled it just below rim and checked again. This winter I had to relevel my tank from the screwy winter we had. I just drained 10g off to see the water line and got my bro to use a small prybar under it so I could get a bigger one under the stand to lift it another 3/16" then put thicker steel shim in

Actually it is the point of the thread, to determine how much it matters for tank to be off level. That said I'm also glad you polish glass for living, I'm a professional stress engineer, I design tanks and vessels among other things and on top of that I even use to build aquariums.

The simple fact is if a tank is built and supported properly then there are no pressure points. The only stress is created from the pressure from the water and that doesn't change if the tank is not level, running a wave would have a much higher affect and even that isn't enough to over-stress a tank. These pressure points your talking about are result from uneven glass edges contacting one another, this will cause issues even if the tank is perfectly level. Also shimming a tank isn't a good idea, the stand should be shimmed and the tank receives even support. This is why foam is often used and recommended to provide even support the base of the tank. This is what is critical, not the level.

Woah, I didn't mean to imply the tank itself should be levelled, but instead the stand
I may have used the word 'tank' in general as a reference to the whole unit :smile:

Thanks for the clarity on this sphelps

Thank you for making that very important distinction. I totally neglected to mention what I was shimming. I shimmed the stand (an old dresser), and not the tank, to get the tank close to level.

Speedy fingers!

I went to butter my toast In the middle of writing my reply and didn't see yours.

Yes, toast for supper. This hobby is leaving me broke. :lol:

Good stuff, it's also a good idea to check if the surface the tank sits on is perfectly flat, if not you should use some thin foam or rubber under the tank to even it out. If it's already running you can't really do much though.

I should add that leveling a tank is a good idea, it's an easy task and everything will look and work better but being off won't cause it to break, that's just silly.

I can fit a piece of paper between the trim and the stand on the front over a length of around 6". I missed that earlier. I checked that the centre of the tank was in contact with the stand. The gap is to the left of centre.

I've got around 15 gallons in the tank so far. Is it important enought that I should drain it and use the foam?

If so, could I use layers of laminate flooring underlay? We've got piles of scraps of that (Hubby installs wood floors for a living).

My 175g has always been out of level currently by about 1/2" both front to back and left to right. The tank has Been moved several times since I got it about 4 years ago I'm pretty sure that the guy that had it before me had it out of level. The stand is flat on both top and bottem so the entire thing is tilted.

Yeah if you're just filling it and you got 15 gallons in there, it would be wise to drain it seeing how it's possible some of the tank may not be supported completely. Foam underlay really isn't ideal as it's not very rigid but it would be better than nothing, just make sure it's even and not making things worse. What can work quite well that is readily available and not an eyesore is the one sided black foam tape. It's used for insulating things like attack access hatches and other generic applications, available at pretty much any hardware store. You can just stick to bottom of the tank frame itself.

I'll see if I can find the tape. TY!

Woah! Placed our new display tank on its stand last night. There is a very significant gap (1/8" or more in some places) between the black plastic trim and the stand on three sides of the tank.

I've found a couple of different types of foam tape. I have found "expanding" foam tape (an automotive product, but I think it is too thick), and weather stripping foam tape (in various thicknesses, and open and closed cell). Is one of those types of tape what I should be looking at?

This is only my opinion, and anyone else who says otherwise is not connected to me ... blah, blah, blah, ......

I am very concerned about what you have said with your gap between your stand and tank
Do NOT try to fill the gap with something ....
Your stand, IMHO, should be as tight a fit to your tank as possible ....

IMHO, no foam will ever alleviate / fix compression of our tanks ...

Put your tank on it's stand and let the carpet settle, 1/2 day, all day, all weekend, whatever .... fill it and let it settle
Next, put RO water in it to the full line and level it when it's full ....
Now you can play with the level limits ...

The most rigid tape foam you can get is fine, you don't want an expanding foam or anything that compresses too easy. A better choice given the gaps being noticeable and what most people typically use is the 1/2" pink rigid foam from the insulation department but it's pink so not always the nicest thing to look at unless you cover the edges with tape or something. Ideally the stand should be better but 1/8" isn't terrible, rigid foam will compress with the tank and water weight enough in the right places to seal any gaps in support.