Concept Aquariums 750G Fish Only

[sphelps]

One day we're going to have a discussion about how pressure works, width doesn't limit length or height provided width <= length.

[lastlight]

Steve are you saying any safely designed rectangular tank can actually be as wide as it currently is long without issue?

[sphelps]

Originally Posted by lastlight

Steve are you saying any safely designed rectangular tank can actually be as wide as it currently is long without issue?

Yes, the only difference relates to the base which will have a higher load but provided your stand supports it properly it's not an issue.

Tanks are governed by three things, static pressure, hydrostatic pressure force, and seam stress. Static pressure is just density x gravity x height and has nothing to do with length or width. The hydrostatic force is the outwards force from static pressure, can be applied as equivalent at center of pane. This force creates a bending moment at your seams, the longer the moment length the higher the moment, so the governing dimension will be the longest length, additional width does not matter provided it does not exceed length. Seam stress comes from static pressure and hydrostatic force but can be reduced by larger seams (thicker glass), it will mostly relate to bending moment so again limited mostly by length. So when designing a tank things to consider are maximum length and height, then it's just a matter of choosing the appropriate glass thickness to satisfy three governing load cases. The results will be identical for both LxWxH & LxLxH provided W<=L, again this is excluding the base which should be considered in the stand design.

[denny_C]

Originally Posted by sphelps

One day we're going to have a discussion about how pressure works, width doesn't limit length or height provided width <= length.

i agree and pressure is one thing but we have to make sure we dont get sued or kill someone if a tank this large were to come apart, we have alot to lose by not sticking to what we feel are safe dimensions , theres certain dimensions where sure we can get away with a thinner glass or max out dimensions but most people dont mind paying for peace of mind and for us a little bit of restrictions in what we do for glass sizes allows us to go without incident.

at the end of the day its about what we feel comfortable selling or building, and the last thing we want is to cause anyone any house or business damage, with this tank in particular this was the space we had available and the glass we were able to get at the time.

[denny_C]

over 2000 tanks under our belt and weve never had a blowout,break or seam tear apart(that i know of) so i feel like we are doing a good job on our glass choices and size restrictions

[sphelps]

Well as long we're clear you're designing based on feelings and not math I'm fine with that . Just pointing out you often note width as a limiting design factor but as far as science is concerned it's simply not the case.

[Delphinus]

I might have just said something like "because we wanted space for people to walk in front of it."

[denny_C]

Originally Posted by Delphinus

I might have just said something like "because we wanted space for people to walk in front of it."

space was a limiting factor for sure when we chose the dimensions , we obviously didnt have 17ft of width to use lol

[dave_C]

Originally Posted by Delphinus

I might have just said something like "because we wanted space for people to walk in front of it."

that and we just didn't know what this old building had for a foundation made it hard to go anything large than i was comfortable with

i had orginally wanted to do 48 inch wide but just couldn't make it fit with the layout of the store

[denny_C]

Originally Posted by sphelps

Well as long we're clear you're designing based on feelings and not math I'm fine with that . Just pointing out you often note width as a limiting design factor but as far as science is concerned it's simply not the case.

i know we have never seen eye to eye on glass sizes and dimensions but its been working for us so far and its not worth the risk for us or the risk to our customers , by doing it the way we do we dont have to question alot of this science or push its limits,again its what we have come to practise and so far seems like a good guideline for us and has carried us this far.

the industry is not regualted by code or anything like that so its always a companys name/insurance on the line and alot of what we do wasnt made up off the top of our head its common practises for alot of builders to ensure they dont cause anyone any damage or harm, and l;essons learned from those who have.

one blowout in the game for a miscalculation and end of the line it is for us or any builder for that matter.

at the end of the day we have our size restrictions that we stick to , while im sure it will differ from builder to builder our prices are low , quality is good and we have a great track record so i dont see the need to change the way we do things

cheers

denny