Leveling of my 600 Gallon.

[Lepisosteus]

Personally I think the acrylic tank itself may have a very slight bow on the bottom as a result of cell structure collapse of the foam.

can we at least say I nailed it back in post 17? Anyways, to fix this I would shim the plywood to the stand personally then shim all around and under the plywood to ensure full contact. Is that tank 3/4” or 1” acrylic? You do not need to use marine grade plywood, most don’t. The guy on contract with us who builds stands does not. If you pour that much water onto the plywood UNDERNEATH your tank to cause it to warp then you should reconsider how you do water changes and consider adding lids

Just my 2cents

 

[neoprodigy]

can we at least say I nailed it back in post 17? Anyways, to fix this I would shim the plywood to the stand personally then shim all around and under the plywood to ensure full contact. Is that tank 3/4” or 1” acrylic? You do not need to use marine grade plywood, most don’t. The guy on contract with us who builds stands does not. If you pour that much water onto the plywood UNDERNEATH your tank to cause it to warp then you should reconsider how you do water changes and consider adding lids

Just my 2cents

yes you did.. so I should shim the the wood?

 

[neoprodigy]

or should I fill the tank up to about 1/3 and try to warm it up as much to "reshape" the tank?

 

[RemainVayne]

yes you did.. so I should shim the the wood?

I'm not an expert at all despite how much I've Googled about this over the past month, but I would shim before filling.

Any signs of seam separation or excessive crazing in any one spot?

 

[Lepisosteus]

Interesting topic. Was going to suggest filling it so it self levels but no idea what that could do to the tank. Why I was asking about the thickness. 3/4” would be more comfortable than 1”. If it was my tank I’d likely fill it and see what happens knowing I can get another one relatively easily. For someone else’s tank though I’d suggest the shims

 

[esoxlucius]

The way i look at it i think you've got a real problem here, and it's made worse by the size of that monster and the weight/pressure once filled. You could ensure your stand top is absolutely true and flat. Sit your warped tank on top and slowly fill. At some point the weight of the water coupled with the flex of the tank will mean that your tank will sit snug against the ply, probably. However, whether it sits true against the ply after quarter full or half full or whatever, you will know that those joints will have had to flex to achieve it's correct position. That flex is what would worry the hell out of me. The tanks panels will naturally bow anyway and then on top of that you've got a slight unnatural twisting motion going on too in the joints. To me, once that monster is filled, there would be a massive question mark over the whole structural integrity of the tank.

If you somehow shimmed between ply and tank then you'd be creating an uneven place for your tank to sit on, which would look fine when your empty tank is sat there looking all flush. Then you fill it and that bottom panel of your tank is being forced, by the immense weight of the water, to take on a new shape because of your shims. When that bottom tries to take its new shape you're back to square one with the stress on the tank joints again.

That's how I look at this problem. I really hope someone comes up with a solution. If not, take a flyer on it and start using it, but make sure you put it in your garage or somewhere where potential damage will be minimal.

 

[ReApEr666]

All acrylic tanks bow... even the bottoms...even brand new tanks will be shaped to the piece of wood they were built on. Y some manufacturers make and sell the tank on the same sheet of 3/4" ply it was built on. they actually glue the wood to the bottom of the tank. This is nothing to be worried about. Lepisosteus is spot on as usual. 1st shim the stand as needed between the stand and floor. 2nd shim between the stand and ur plywood. the most important part to keep supported is the outer perimetter (bottom seam). You can use as many shims needed as necessary between the plywood or even between the tank and plywood to fill in any "air gaps". Every used acrylic tank ive owned had a bowed bottom...this is all just part of setting one up IMO... no stand is 100% true...material is not 100% true either so we need to literally fill in the gaps as best as we can with shims so no seam seperation is possible. My acrylic tanks are 25-30yrs old and are shimmed everywhere to compensate for any discrepencies. If youve never owned or setup an acrylic tank...please do not confuse the O.P. 2 many people are misinformed in this process and theres alot of misconceptions such as foam under acrylics and apparently shimming aswell. Nothing catastrophic can happen if u properly shim between the plywood and stand. With the weight supported seam seperation isnt possible.

This is always a poor example...but a valid one... watch an episode of "tanked"... they deliver the tank with the wood glued to the bottom... then shim under that wood on top of the metal stand. this is all planned out for a reason. no foam...no b.s....

 

[krabbo008]

I just posted a similar thread w. Alot of the same questions-that are getting answered here.

 

[CarpCharacin]

No

 

[Lepisosteus]

However, whether it sits true against the ply after quarter full or half full or whatever, you will know that those joints will have had to flex to achieve it's correct position. That flex is what would worry the hell out of me. The tanks panels will naturally bow anyway and then on top of that you've got a slight unnatural twisting motion going on too in the joints. To me, once that monster is filled, there would be a massive question mark over the whole structural integrity of the tank.

Why I didn’t recommend filling it. If it was my tank sure, but for someone else’s containing 600 gallons I’m a little more weary. Take the tank off the stand, out into garage on 2x4s and a piece of plywood, make sure it’s level. fill it up and see if it contorts back.

All acrylic tanks bow... even the bottoms...even brand new tanks will be shaped to the piece of wood they were built on. Y some manufacturers make and sell the tank on the same sheet of 3/4" ply it was built on. they actually glue the wood to the bottom of the tank. This is nothing to be worried about. Lepisosteus is spot on as usual. 1st shim the stand as needed between the stand and floor. 2nd shim between the stand and ur plywood. the most important part to keep supported is the outer perimetter (bottom seam). You can use as many shims needed as necessary between the plywood or even between the tank and plywood to fill in any "air gaps". Every used acrylic tank ive owned had a bowed bottom...this is all just part of setting one up IMO... no stand is 100% true...material is not 100% true either so we need to literally fill in the gaps as best as we can with shims so no seam seperation is possible. My acrylic tanks are 25-30yrs old and are shimmed everywhere to compensate for any discrepencies. If youve never owned or setup an acrylic tank...please do not confuse the O.P. 2 many people are misinformed in this process and theres alot of misconceptions such as foam under acrylics and apparently shimming aswell. Nothing catastrophic can happen if u properly shim between the plywood and stand. With the weight supported seam seperation isnt possible.

This is always a poor example...but a valid one... watch an episode of "tanked"... they deliver the tank with the wood glued to the bottom... then shim under that wood on top of the metal stand. this is all planned out for a reason. no foam...no b.s....

Well put.