Hmm… google says the 8mm donor tank is eurobraced, no plastic rim/frame… that likely explains the thinner bottom glass! — I’m surprised it isn’t tempered as a bottom pane at only 8mm thick, though!
Tank build. From scratch.
- Thread starter rgvEddy
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rgvEddy
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Not sure if this helps at the top but could definatly brace the bottom for some extra strength. I have plent of glass left.
I erm flooded the house a couple of years back after fitting a kitchen. Reused a kinked flexible pipe i couldnt replace locally then went on holiday. Id rather be double safe
I erm flooded the house a couple of years back after fitting a kitchen. Reused a kinked flexible pipe i couldnt replace locally then went on holiday. Id rather be double safe
The plastic rim also hides bad silicone work on the bottom seams; though its intended purpose is actually structural!
That top eurobrace also looks like a decent idea! — while not strictly necessary; I’ve seen more completely rimless tanks peeling apart from the top down than I would like…
I think the bottom “eurobrace” is the more important of the two in this case… Also, consider doubling up glass thickness for the bottom pane inside the overflow box (as part of the bottom eurobrace, possibly?) — this will give you a much stronger area to install your bulkheads into!
rgvEddy
Community Member
I cant get inside the overflow as its too narrow but my thoughts were that the overflow adds strength to a degree. Also. When fitting i thought of doubling but the thread length on the bilkheads would be barely holding onto thread.
Il cut and double up the bottom tomorrow and go from there. Im tryinging to overengineer at ebery step for future piece of mind do its all good
Il cut and double up the bottom tomorrow and go from there. Im tryinging to overengineer at ebery step for future piece of mind do its all good
Metric plumbing is measured by outside diameter, vs. inside diameter for imperial plumbing!
— that said, 20mm is around 16mm-17mm ID; so roughly 5/8” ID! Knowing this, it is capable of flowing roughly 600-700LPH in a gravity drain application!
You can definitely cut slots in the glass if you have a grinding tool like a continuous rim diamond circular blade!
The water height will be dictated by how wide the slots you cut are, and how much flow you are pushing through the slots! (Also, total weir length)
If cutting slots directly into the glass, I recommend siliconing another strip of glass flat on top of the slotted edge, forming a T shape as a cross-section, this will significantly increase the strength of the glass between each slot!
I recommend no narrower than 3mm for your slots, at least 20mm tall.. ideally make your slots closer to 5-7mm wide! —you can cut them in a V shape, making them perform better and better as they get clogged over time and the display water level rises sightly!
Here’s the overflow in my 110L hexagon; roughly 35cm of overflow slots, ~1,700lph observed return pump flow… they are 25.4mm tall per- slot; the bottom 12.7mm is a straight slot, 3.7mm wide. The top 12.7mm is V shaped; expanding from 3.7mm to 6.35mm.
Water sits right at 10-12mm up the slots on this overflow during normal operation; right at the point where the slots begin to widen… this substantial amount of water piling up against the teeth without draining through is partially due to relatively high flow, and partially due to the thin slots causing the salt water to create a meniscus, not wanting to break surface tension through a small slot without additional pressure forcing it to!
What about using just a thin glass rod inside the overflow box to reinforce the bottom seam there? How much space do you think you will have between the bulkhead flanges through the bottom of the tank, and the rear vertical glass?
rgvEddy
Community Member
I will line the bottom with extra bracing. Iv allowed 2.5cm or 1nch coverage of wood so seams are not seen at the bottom.
Thanks for the wier info but i went with a d-d high flow weir. But inside out to reduced footprint. Top tank drains into overflow of bottom tank as its ofset by 20mm ish. On testing with a 1000l hr pump theres loads of potential flow as the gates are barely open. Il post a video in a mo of test plumbing.
Once i get the fleece filter in i can start to see what my limits are as im guessing that might be the bottle neck. Bought a neptunian cube fleece filter but rebranded chinese version. Top tank sps but flow provided by powerheads.
Bottom tank zoas etc and flow from return only.
Thanks for the wier info but i went with a d-d high flow weir. But inside out to reduced footprint. Top tank drains into overflow of bottom tank as its ofset by 20mm ish. On testing with a 1000l hr pump theres loads of potential flow as the gates are barely open. Il post a video in a mo of test plumbing.
Once i get the fleece filter in i can start to see what my limits are as im guessing that might be the bottle neck. Bought a neptunian cube fleece filter but rebranded chinese version. Top tank sps but flow provided by powerheads.
Bottom tank zoas etc and flow from return only.
Very nice! I’m surprised it can handle so much flow! — that’s a full siphon at work I suppose!
As far as top bracing; it doesn’t really need the full eurobrace treatment, and that would really cut down on room to reach in and work on the tank!
— Here’s a design I’ve been playing with recently… simple right triangles of glass used as “semi-eurobraces” for the top corners of the tank! They serve to reinforce each vertical seam in each top corner, without consuming as much of the access hole in the top of the tank as a true full eurobrace does!
rgvEddy
Community Member
With regarxs to water level. My main issue is small return chamber in the sump. Now, iv got it fairly tight in terms of drainback but iv noticed that over 5 mins or so the water can seep around and under the weir plastic adding a liter or two. Il silicone all gaps but its not unsubstantial when return chamber is only 4 litres or so.
rgvEddy
Community Member
That would work easily
Very nice! I’m surprised it can handle so much flow! — that’s a full siphon at work I suppose!
As far as top bracing; it doesn’t really need the full eurobrace treatment, and that would really cut down on room to reach in and work on the tank!
— Here’s a design I’ve been playing with recently… simple right triangles of glass used as “semi-eurobraces” for the top corners of the tank! They serve to reinforce each vertical seam in each top corner, without consuming as much of the access hole in the top of the tank as a true full eurobrace does!
rgvEddy
Community Member
On all 4 cornersThat would work easily
Very nice! I’m surprised it can handle so much flow! — that’s a full siphon at work I suppose!
As far as top bracing; it doesn’t really need the full eurobrace treatment, and that would really cut down on room to reach in and work on the tank!
— Here’s a design I’ve been playing with recently… simple right triangles of glass used as “semi-eurobraces” for the top corners of the tank! They serve to reinforce each vertical seam in each top corner, without consuming as much of the access hole in the top of the tank as a true full eurobrace does!
I would just cut out the baffles in the sump, or use glass for the weir and bubble trap baffles! — acrylic can expand up to 3% (more for extruded) when submerged! I’ve seen acrylic baffles cut to fit snug inside a glass tank actually break the tank itself!!
You’ll want to cut the glass baffles around 3-4mm shorter than the inside dimension of the sump tank, leaving space to inject silicone into the gap on both sides!
(Use blocks of wood or whatever you have around as shims to hold the baffles in place, and the correct distance away from each-other while the silicone dries overnight!)
If you’re worried about your return pump sucking up bubbles, you can always build a removable plastic box around it that sucks water in from the bottom only!
Yes, all four corners! 60mm-80mm short legs of each glass triangle should be more than sufficient bonding area to effectively reinforce the top corners, helping to resist the natural urge of an open topped box to peel itself apart!
rgvEddy
Community Member
Hello. Been busy. I wasnt happy with the tanks so stripped them down and remade them. That was very time consuming but worth it.
First time round i used the press and guess tecnique. Thats not easy and when i stripped the doner tanks i noticed inconsistanies of silicone thickness.
Secong time i used the injection methon. Night and day difference. More waste but less mess and much better finish. Takes all the guess and a lot of tecnique out of it. Once clamped up with everything in place its soo much easier as its already built plumb square etc.
I also braced the crap out of them as i had thd glass and made my sump slightly bigger. Main display now has double base and lots of bracing. Thanks for pointing out the need for that.
It is now literally built like a tank.
Please see picks
First time round i used the press and guess tecnique. Thats not easy and when i stripped the doner tanks i noticed inconsistanies of silicone thickness.
Secong time i used the injection methon. Night and day difference. More waste but less mess and much better finish. Takes all the guess and a lot of tecnique out of it. Once clamped up with everything in place its soo much easier as its already built plumb square etc.
I also braced the crap out of them as i had thd glass and made my sump slightly bigger. Main display now has double base and lots of bracing. Thanks for pointing out the need for that.
It is now literally built like a tank.
Please see picks
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