Is there a margin of error in leveling a large tank?

crimzy

crimzy

Active Member
I am now filling the new tank and am wondering if there is an acceptable variation from an absolutely level tank. The tank is 96" x 36" with 3/4" thick acrylic. My level shows the tank to be pretty even in both length and width. However when I measure the water level from the top of the tank I come up with an approximately 1/4" difference in the level from side to side, and also 1/4" difference front to back.
I'm not sure how to level a tank this size as I want to make sure the pressure is equal on all sides of the stand/floor. I also wonder if this small difference may be negligible. Anyone know? Opinions?
 
chilwil84

chilwil84

Active Member
you might want to get a new level. with that said i have a 90 thats 4' thats at least a 1/4" out and its has been fine for 2+ years and it spent 5 years as a reptile tank prior so it has been through some dry hot times. not sure if this gives you a better piece of mind with an acrylic tank.
 
crimzy

crimzy

Active Member
Originally Posted by dirtee147
http:///forum/post/2718832
I would get a new level also.How big is the level 2,4,6, foot?
The one I used was a 4 ft. At this point, it is a small discrepency, I believe (hope) that this variation is going to be safe... 3/4" acrylic and the variation is only 1/4". Just wanted to see if anyone knew whether I'm likely to have problems with the tank.
 
joncat24

joncat24

Active Member
I would say that a .250 variance over an 8' span is ok. The .250 from front to back is what would worry me. That may put a little torque on the joints.
 
reefkprz

reefkprz

Active Member
1/4 inch isnt bad, but may expose any flaws in the tank sooner than you may like. my 75g allglass is out 1/4 inch from side to side. honestly making sure the top of the stand is even is more important than absolute level.
that said getting it as level as possible is ideal.
 
crimzy

crimzy

Active Member
Actually the variation from front to back is a bit less than 1/4"... it's more like 3/16" or slightly less.
I think that most tanks have slight variations in them, (at least most of the tanks I've had have). At this point, I think that it will be fine as there's not much I can do about it.
Thanks for the opinions.
 
veni vidi vici

veni vidi vici

Active Member
I used a laser to to level my stand
But if you have any doubt about the accuracy of your level you can use some clear tubing and some water to check it.Since water will seek its own level, take about 10' of clear tubing, 3/4" ID should work.Fill it with water and leave about 6" of air in the tube at either end when holding tube together folded in half.Hold both ends up at around eye level and mark the tubing at water level with a sharpie or any other marker you have lying around.One end of the tube will be stationary on the high point of your tank,you will have to find it using the water level.After you find the high point ,start checking you other corners and center points.On the non stationary end of the tube,if you hold the mark on your tube even with the top of your tank and the water is below the line then the tank is high at that point if the water is above then it low..... This is important ....make sure there are no air bubbles in the line before you start.
 
scsinet

scsinet

Active Member
I agree with those that are saying you are within an acceptable tolerance, especially for acrylic.
The thing to remember is there is level and then there is planar. Planar is what is most important, that is that your tank is sitting on a flat surface. A bit out of level is okay, but if you have one corner of the tank off by 1/4" from the others, the weight of the water exerts tortion stress on the tank and can cause serious problems.
So most importantly, if your tank is off by 1/4" from side to side across the back of the tank, it should be equally out of whack on the front. If it's 3/16" off from front to back on the left, it should be the same on the right.
You've got an acrylic tank which is easily forgiving of this deviation, so you should be fine.
 
veni vidi vici

veni vidi vici

Active Member
Originally Posted by SCSInet
http:///forum/post/2726971
I agree with those that are saying you are within an acceptable tolerance, especially for acrylic.
The thing to remember is there is level and then there is planar. Planar is what is most important, that is that your tank is sitting on a flat surface. A bit out of level is okay, but if you have one corner of the tank off by 1/4" from the others, the weight of the water exerts tortion stress on the tank and can cause serious problems.
So most importantly, if your tank is off by 1/4" from side to side across the back of the tank, it should be equally out of whack on the front. If it's 3/16" off from front to back on the left, it should be the same on the right.
You've got an acrylic tank which is easily forgiving of this deviation, so you should be fine.
Good to see you back.You must have your new ISP
 
crimzy

crimzy

Active Member
Thanks for the replies guys. Now that the tank is filled, it has settled a bit and the variance from front to back is only 1/8". At this point I can't really worry about it or I'll make myself crazy.
 
waterworld

waterworld

Member
As was mentioned you want to be flat. Do not worry as much about level. You want to set the stand on the floor and shim all around between the stand and floor. This closes up all of the gaps and spaces that would allow the stand to "Settle". Then set the DT on the stand and shim between the stand and the tank. Some people use foam of some kind for this. (I use the truck camper tape) You do not want the tank to settle in the foam and rest on the glass. A glass tank must sit on the rim. IF your tank does not sit on a flat surface it will not be supported all around and end up twisting and fail. Very and most important is that all of the corners are resting solid on the stand. I found out the hard way when after two years my 125 blew apart and the worse happened. The manufacturer in reviewing the tank pictures said it was a classic case of tortional stress fro mbeing in a twist.
You do not wnat your tank to settle after it is set up and filled. If it settles it most certainly will not settle consistant all around.
Good Luck
WW
 
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