new acrylic tank not square--now what?

[mathman7728]

all,

just discovered that new acrylic DT (180gal 3/4" acrylic) isn't perfectly square (off about 1/16-1/8"). the result is that while the stand is perfectly level in all directions there is a corner of the tank that sits about 1/8" gap between the bottom of the tank and the top of the stand. :headwalls:

is this gap a big deal? i know that acrylic can bow out a bit once filled with water, etc so i wonder if this gap is something to worry about.

 

[Timfish]

I would go to your local home improvement store and get a package of shims that are used for squaring door frames in walls. Just slide the shims in til snug and snap them off.
If you don't ever want to remove the tank off the stand you can use a foaming urethane glue that will fill the gap, also available at home improvement stores.

 

[usingthejohn]

You could also place the tank over some 1/4 or 1/2" foam they sell at Lowe's or home Depot. The tank will mold into the foam.

 

[azjohnny]

You could also place the tank over some 1/4 or 1/2" foam they sell at Lowe's or home Depot. The tank will mold into the foam.

I did this with a 3/4" foam sheet from HD that is used for ceiling insulation

 

[mathman7728]

i tried to shim the problem away when i thought it was the stand. shimmed that damn stand till it was level as level could be. lifted the tank on the stand….again…(it weights at least 200lbs). still had the same problem and than is when i took out the carpenters square and found the problem is the tank. i have a thin sheet of horse mat under then DT as it is…still have the gap (the mat isn't very compressible--i guess they don't want it to be given horses walk on it). the issue with shimming is that i have to use a LOT of shims to bring the whole stand out of level (to match the DT).

someone on this forum said using foam to level the DT wasn't a good idea…not sure why.

 

[ThreeMoneyJ]

Foam under a RIMMED tank is bad.

Foam under a RIMLESS tank is good.

 

[mathman7728]

curious as to why it is good for rimless tank and not good for rimmed tank

 

[Indymann99]

When you fill the tank with water you will not have the gap.

 

[mathman7728]

I did this with a 3/4" foam sheet from HD that is used for ceiling insulation

would the pressure vary across the bottom of the tank and therefore lead to failure??

yes, i know perhaps i am a bit up tight about this but the tank is in the basement which we had to have redone because a failed frig water filter while on vacation. flood took out the entire basement, wife and insurance company were not happy and we don't need to go through that again.

 

[ThreeMoneyJ]

On a rimmed tank te rim is meant to take the pressure and not the glass. If you use too thick of a pad the rim may sink in too much and then the glass would be touching the pad and getting pressured.

On a rimless tank the pad alleviates any point loads on the bottom pane which may lead to a failure of the bottom pane.

 

[azjohnny]

I bought my 180 used and it had a 1/16"-1/8" bow in the bottom with bow being the biggest in the center of the tank and filing with water made no difference. The builder used 1/2" acrylic on all the panels except the bottom where he used 3/8" and I am assuming that is what caused the bow.

When I noticed the bow I emptied the tank of water and used the foam to help stabalize. I have had the tank for about 3 yrs and so far no issues aside from a small amount of water leaking into the overflow from where the overflow meets the back of the tank

The tank the OP has is acrylic so it is not rimmed

Acrylic is a lot stronger the glass and I think you will be ok, the seams are as strong as the acrylic itself

 

[planedoc]

I had a 1/4 gap under one corner of my brand new acrylic tank. Verified my stand was square and than I filled the tank and within a few days it straightened out. It's plastic and can and will Bend. If it's stored or shipped on an uneven surface it will become warped. Like in my case it will straighten out once warm water is added. I think it's better to let tank straighten vs shimming it. You really don't want a crooked tank. Measure all the sides and verify it's made correctly and you will be fine.

 

[mathman7728]

thank you!!!!

 

[Indymann99]

would the pressure vary across the bottom of the tank and therefore lead to failure??

yes, i know perhaps i am a bit up tight about this but the tank is in the basement which we had to have redone because a failed frig water filter while on vacation. flood took out the entire basement, wife and insurance company were not happy and we don't need to go through that again.

Acrylic tank and Bean or Herbie silent failsafe drain design are your best bets.

My basement 120g

 

[accordsirh22]

thats a sharp room

 

[EnderG60]

If it was glass I would shim it or use foam.

for acrylic id return it, dead serious. acrylic needs to be evenly supported over the entire bottom and any extra stress will cause a crack eventually.

Get a different tank.

 

[tkeracer619]

Installing an acrylic tank and letting it flex to match the stand can cause premature failure.

Acrylic tanks are generally installed without foam.

Most of the time with glass tank a rim means the bottom pane is floating. If you put foam under a tank with a floating bottom the bottom silicone joints are in sheer which is bad. On a flat bottom glass tank with no rim the bottom takes the load and supports the side panes, foam goes under this. Miracles wants foam because it is not floating even though it has a rim.

Since this is acrylic I would see what your options are for another tank. If there is nothing you can do about it I would put some bondo on the stand that corresponds to the unlevel part of the tank, cover it in plastic, and sit the tank on it. Once dried move the tank, put 1/4" foam between the stand and the tank, never look back.