can we revisist the subject of tank leveling?

[RoxyDog]

I was gonna ask in Jason's thread, but didn't want to threadjack! 
Can I get some opinions again (I know this topic has been visited before but couldn't seem to find the thread?) about when you *need* to level your tank?  For instance, I have a 77 gal that is not level side to side by I'd say 1/2 a centimeter (which looking at a ruler is bigger than I remember).  BigDaddy warned about tanks being off by even a fraction of an inch...should I be emptying my tank and fixing it?  All you experts out there chime in please?!

[artw]

I have always made sure my big tanks are level to within 1/4 of an inch,  but in my highrise on Fisher when the wind blew, the water would go up and down (as the building swayed back and forth) about 1-2" at either end.  and that didnt cause any problems, however it wasnt a sustained load such as you would encounter with an unlevel tank.
Aquariums are built to be structural at the corners and ends, so if you have an uneven stand or a stand that doesnt support the entire bottom of the tank even though the waterline is level you will still have a point load at the corners which = bad news.

Bottom line. Level stands, square stands, level waterline = more gooder. ask Darkdep. I bet he agonized hours and hours and hours about making his rack perfectly square to a tenth of a degree.

[FishBuddy]

You beat me to it Roxy!  I was asking myself the same thing a few minutes ago...

Perhaps in one of our upcoming meetings, could we get someone to give a quick presentation on the importance of levelling a tank, as well as some of the basic tips/techniques?  Also, perhaps mention the importance of having a water leakage alarm installed for a huge tank to minimize a total disaster that we have just witnessed???

Having seen a few of these diasasters now, I am seriously planning to get a water alarm of some sort...

[Jason]

The only thing about a water alarm is that in a case like mine by the time the alarm goes off your tank and all it's contents are on the floor. The good thing about an alarm is that I could have at least saved my fish.

[artw]

well I'd think if a seal let go you'd probably know about it. it's not exactly a quiet event.  I remember dropping a rock on one of my 40's and it emptied in about 2 seconds.
I would think if we are careful with moving our tanks, make sure the silicone is good, and making sure the stands and floor supports are square and even,  we don't have anything to worry about. a water alarm would be equivalent to having your air bags in your car deployed all the time - not really useful.

[darkdep]

Leveling your tanks as much as possible is very important; although much less so for smaller tanks.  You can have a 20gallon tank on a steep angle and it'll hold for years.  A 6' tank tho, should be level to within 1/8" both ways, and completely supported. 

A LOT of people (including me!) build their own stands out of 2x4 material.  The problem with 2x4 material is it just isn't straight; it's not terribly important for their intended application.  What I do when I build out of this material is hand pick the straightest I can find, assemble, handplane a bit, and ALWAYS put a piece of plywood on top.  And on that always goes a piece of 1/2" styrofoam.  This combination produces a surface that absorbs some of the un-straightness of the material, as well as deals with uneveness in the top. 

If you have a 4' tank (as you do, Roxy), I wouldn't worry about 1/2cm. 

I think in Jason's case the frequent moves may have had a part in weakening the silicone.

[artw]

For show tanks, if you dont want to use ugly styrofoam,  thin dark green carpet underpad works just as well.  and you can't see it. When I sold my 110, the carpet pad ended up being sliver thin at one end and over 1/4" thick at the other end.