Building glass tank from scratch

[Kyplies]

Hey whats going on? I am new to R2R and the hobby. I did have a 25 gal reefer about 10 years ago but that was short lived. I've interested in getting back in the hobby again. I've been wanting to build a tank from scratch. I like the dimensions of the reefer 250 I'll probably make it bigger. I am kinda stumped with a couple of questions. What do you guys think?

How big should the drain, emergency drain and return pipe hole be? ( placed on the bottom of the tank)

Tempered glass or plain?
(Saleswoman wants to sell me tempered glass, she said she might be able to drill the holes prior to tempering the glass pieces but needs to know where the holes are to be located)

If someone else has done this point me in that direction please. Look forward to hear from you guys!!

Kyplies

 

[lapin]

Howdy and welcome.
I would not use tempered glass.
For a 50 gallon tank 1" pipe might be fine depending on the type of overflow box and pump you are going. to try and use.
I would do some research on overflow types before starting the build

 

[DJKNOX]

So from a structural engineering perspective, the panels of an aquarium must deal with both bending stress and risks due to deflection. Although in theory safety factors on stress are all that is needed, in actuality it is deflection that introduces the biggest risk to panel failure. Heat strengthened glass and in the limit tempered glass - has an increased maximum allowable stress that can be 2x to 5x stronger. So in theory, tempered glass can tolerate multiple fold stresses over normal float glass. However, here is a secret one doesn't see mentioned very much on hobbyist chat forums: tempering glass does not decrease deflection! Deflection is a direct function of the material's elasticity as measured by its Young Modulus "E" and tempering glass has little impact on the value of E. So although tempered glass in theory can tolerate more stress - ie it is stronger, it will deflect equally. There are different guidelines concerning how much deflection is acceptable, but in general for an aquarium it is recommended that the deflection over the length of the panel be less than the thickness of the material... and preferably a lot less. The stresses at such limited deflections are well below allowable stress levels. To achieve a limited about of deflection, stiffeners are often utilized - often referred to as euro-bracing. Cross bracing is also effective. Simply put, it is not the stress level but the deflection that aquarium panels are designed to. And in this regard, tempering buys you nothing other than increased "stress safety factors" on paper due to the higher allowable stress levels. But because it doesn't decrease deflections, tempering really doesn't make your aquarium "safer." Note that for some large tank designs, the euro-braces are stressed more than the panels. It is very likely that tempering euro braces would add benefit but I haven't seen such practice and so cannot absolute confirm the benefit.

 

[TDEcoral]

I used 1" PVC for the drains on my 40b and it was overkill. I'm almost done building a 75g and I used 3/4" for the drains and the return. Even with 3/4", the flow through the sump would have to be crazy high to take full advantage of the flow rate that 3/4" can handle.

 

[rq786]

I have built 2ft cube rimless used 1/2” glass non tempered with internal overflow made from gray glass it has two 1” drains and 3/4” return (if I could do it over I would do external overflow box like eshopps box) make sure you to put the tin side outside of the aquarium otherwise tank will have white haze to it