Another DIY Stand Dilemma (75 gallon)

[Squar3Lak3]

Built this stand for a 75. It seems really solid but I know the wood I used was not perfect. There is a slight gap where the tank meets top. The entire stand with empty tank is not level but it’s also not going to be in this location. I guess I’m just wondering if this is ok and also the best ways to help plum the stand from here?

 

[UncommonSense]

This looks close enough that you may even be able to get the stand’s header planed down with some coarse sandpaper, assuming you don’t have any form of planer!

Edit: or… ratchet strap that header down for a day to see if that straightens it out prior to using filled tank weight?

 

[Squar3Lak3]

This looks close enough that you may even be able to get the stand’s header planed down with some coarse sandpaper, assuming you don’t have any form of planer!

I don’t have a planer. I do have palm sanders. I failed to mention I plan on capping with 3/4” plywood both top and bottom. Sides and front will get 1/2”

What is the best way to ensure no twisting as the stand ages? Or how to get the stand more level for the aquarium? I am sure in over thinking it but I just don’t want it to fail OR fall on my kids.

 

[UncommonSense]

I don’t have a planer. I do have palm sanders. I failed to mention I plan on capping with 3/4” plywood both top and bottom. Sides and front will get 1/2”

What is the best way to ensure no twisting as the stand ages? Or how to get the stand more level for the aquarium? I am sure in over thinking it but I just don’t want it to fail OR fall on my kids.

Ah! A plywood top plate, and just empty tank weight should get that bow to the point of being imperceptible, with any luck!

As I understand it, 2x lumber is used instead of 4x lumber not only for price, but because it’s far less susceptible to twisting and splitting as it dries… basically, a stand built out of 4x is more liable to deform after it’s built!

In a typical RocketEngineer-style lumber stand build, the stand is assembled while the 2x lumber is still green (wet), then the filled tank weight keeps the lumber fairly flat as it dries! (That’s my interpretation, at least! I’ve taken apart, and/or examined a fair number of stands with a wide array of build qualities, styles, and materials… typically, all but the most questionable will remain fairly flat once they dry out with all that weight on them!)

 

[Squar3Lak3]

I don’t have a planer. I do have palm sanders. I failed to mention I plan on capping with 3/4” plywood both top and bottom. Sides and front will get 1/2”

What is the best way to ensure no twisting as the stand ages? Or how to get the stand more level for the aquarium? I am sure in over thinking it but I just don’t want it to fail OR fall on my kids.

Ah! A plywood top plate, and just empty tank weight should get that bow to the point of being imperceptible, with any luck!

As I understand it, 2x lumber is used instead of 4x lumber not only for price, but because it’s far less susceptible to twisting and splitting as it dried… basically, a stand built out of 4x is more liable to deform after it’s built!

In a typical RocketEngineer-style lumber stand build, the stand is assembled while the 2x lumber is still green, then the filled tank weight keeps the lumber fairly flat as it dries! (That’s my interpretation, at least! I’ve taken apart, and/or examined a fair number of stands with a wide array of build qualities, styles, and materials… typically, all but the most questionable will remain fairly flat once they dry out with all that weight on them!)

My wood is pretty dry as I’ve had it over a year. The support 2x6’s are fairly green however. There is a slight bow in try bottom long piece which has me concerned but I’m hoping a plywood bottom would cover that up.

 

[UncommonSense]

My wood is pretty dry as I’ve had it over a year. The support 2x6’s are fairly green however. There is a slight bow in try bottom long piece which has me concerned but I’m hoping a plywood bottom would cover that up.

in this case, see how things look with the plywood on it; plywood can in-itself have some pretty egregious defects (thicker spots where ply seams overlap, for example) unless you get into the really expensive stuff… just take a moment examining a sheet before you buy it!

If there’s still an appreciable bow with everything screwed down tight, and the tank set in place, it might be time to start looking at planing the high spots back, possibly via palm sander or hand planer if they aren’t very substantial! (Or getting some fresh, green lumber to swap your 4ft spans out!)

Edit: it’s worth noting that the (structural) goal is having a flat (plane) surface to set the bottom rim of the tank on, vs. having a perfectly level stand! — you’re just trying to avoid a situation where one corner, or two diagonally opposed corners are appreciably lower than the rest, which would create a twisting force on the tank itself!

 

[Piotrek]

Planning the top and adding plywood would be the best idea. Plywood top is imho the second best. The adjustments you need to make at this point are not that far off. If planning the top is not an option, Additionally to the plywood I would also add a foam mat on top (between the plywood and the glass).
Something like this:

 

[Squar3Lak3]

My wood is pretty dry as I’ve had it over a year. The support 2x6’s are fairly green however. There is a slight bow in try bottom long piece which has me concerned but I’m hoping a plywood bottom would cover that up.

in this case, see how things look with the plywood on it; plywood can in-itself have some pretty egregious defects (thicker spots where ply seams overlap, for example) unless you get into the really expensive stuff… just take a moment examining a sheet before you buy it!

If there’s still an appreciable bow with everything screwed down tight, and the tank set in place, it might be time to start looking at planing the high spots back, possibly via palm sander or hand planer if they aren’t very substantial! (Or getting some fresh, green lumber to swap your 4ft spans out!)

Edit: it’s worth noting that the (structural) goal is having a flat (plane) surface to set the bottom rim of the tank on, vs. having a perfectly level stand! — you’re just trying to avoid a situation where one corner, or two diagonally opposed corners are appreciably lower than the rest, which would create a twisting force on the tank itself!

Ok, I am at least very close. There is only one 4ft span that seems to be “off” and it’s on the bottom, it’s very hard to tell because the garage floor I’m building it in is “level” but still has minor imperfections. I will sand my 2x4 on top to try and make extremely even and then cap with plywood. I bought very high grade plywood and it looks great/smooth so hoping for the best from that.

 

[Piotrek]

Instead of a sander, you could get way better results with this tool (or similar)?

 

[Gumbies R Us]

@Troylee

 

[Fish Fan]

Planning the top and adding plywood would be the best idea. Plywood top is imho the second best. The adjustments you need to make at this point are not that far off. If planning the top is not an option, Additionally to the plywood I would also add a foam mat on top (between the plywood and the glass).
Something like this:

It's not actually a good idea to use foam under a rimmed tank

You absolutely need foam for a rimless tank, but with standard, rimmed tanks, it's best to let the rim support the tank without foam underneath.

 

[Piotrek]

I'm curious, why is that?

 

[Fish Fan]

Built this stand for a 75. It seems really solid but I know the wood I used was not perfect. There is a slight gap where the tank meets top. The entire stand with empty tank is not level but it’s also not going to be in this location. I guess I’m just wondering if this is ok and also the best ways to help plum the stand from here?

I don't think this is too bad at all

I'd add the plywood top, and then get the stand in its final position. Check it then for level and if it's close, I would start to slow fill the tank with tap water. I'd add maybe a quarter to a third of the volume to add some weight, and then double check level all around. In my experience, these 2x4 stands can settle some once they have weight on them.

 

[Fish Fan]

I'm curious, why is that?

@UncommonSense do you agree about no foam under a standard, rimmed tank? This is something I've heard for many, many years. I've personally never needed foam under a rimmed tank. The rim should support the tank all on its own. I don't know if adding foam under a rimmed tank would cause a problem, I just don't think it's needed.

On the other hand, you absolutely do want a foam mat under a rimless tank to smooth out any inconsistencies in the stand.

 

[Gumbies R Us]

@UncommonSense do you agree about no foam under a standard, rimmed tank? This is something I've heard for many, many years. I've personally never needed foam under a rimmed tank. The rim should support the tank all on its own. I don't know if adding foam under a rimmed tank would cause a problem, I just don't think it's needed.

On the other hand, you absolutely do want a foam mat under a rimless tank to smooth out any inconsistencies in the stand.

Yep, I had a foam mat under mine! But mine was the RedSea Max Nano, so I guess that falls into the rimless category, haha

 

[Piotrek]

I've seen stands that bend a bit under the weight of the floated tank. IMHO if the stand has imperfections, the foam would help distribute the pressure. But that's just my opinion, I haven't done any calculations and might be totally wrong. I did however have a rimless 70gallon tank with foam under, that I later moved to another stand with foam. And 80gallon without foam, but the stand was solid and leveled.
Maybe the foam doesn't actually matter...