Pond Glass Problem

[Fresh12]

Built a rectangular outdoor pond that sits on a concrete slab, two sides are double width brick walls and the other two sides are 12 mm toughened glass panes. The glass panes measure 186 cm long and 135 cm long x 59 cm high each (maximum water depth is 53 cm at the overflow). The glass sits in aluminium channel (20 x 20 x 3 mm) which is screwed to the concrete along the bottom and to the bricks up each side. Where the panes come together in the corner there was a 1 cm gap, which I filled with clear Gold Label Pond Aquarium Sealer. The pond was left dry for a week while the silicone cured before filling it up with fresh water. The top metal edging is only decorative, has no structural purpose.

It’s been about 3 weeks since filling the pond and today I noticed that the glass panes have moved. Both panes have pushed out at the top, with the longer pane moving enough that the silicone has peeled away from the glass at the top as seen in Fig.2 below.

Was this problem caused by the width of the silicone? Would a smaller gap between the panes have worked better?

 

[Lisak1]

@Fresh12 - welcome to the GPF! That's a beautiful project! I have no advice about the construction issue you're dealing with, but I'm sure someone will pop in with an opinion.

Are you at all concerned about the whole thing just letting loose?

 

[mrsclem]

So you built a very large aquarium. The top edge needs some support to keep the glass from moving. Aquariums have a heavy plastic frame that supports the glass panels top and bottom, with some tanks having corner support as well. Maybe replace the decorative top with something that will support the glass.

 

[sissy]

I saw a big tank in the car dealership here and they had a metal frame that was welded together .It held 2 thousand gallons of water .The best thing is to empty it before it comes apart and have a frame made for it like Mrsclem said .I wondered how they kept the glass clean and they said they use a magnet glass cleaner .They said they used the same method as the celebrity tank builders show on TV here .Welcome to the world of ponding

 

[j.w]

@Fresh12
Lovely tank you have created and hope you find an easy fix to help it w/the sturdiness around the top.

 

[SherrysPond]

I have large aquariums ( over 125 gallons ) There is tons of pressure on the glass from the water. Google aquarium braces. You need to brace it. Nice tank!

 

[Stephen Noble]

Welcome to the forum! Wow, now that is what I call a hybrid pond. Outdoor pond/aquarium. It looks like a beautiful display one would find in a public aquarium! Well done.
Yeah, a reinforced brace is needed. You might also consider a crisscross brace (through the center) and make is wide enough to place plants upon such as Pothos draping down. It would look magnificent. In any case, you have motivated me to get out of the 'someday I'm going to...' to making it happen. Way to go! As a side note, I have no idea where you live on the continent, but if your temperature range is warmer, your pond would make a spectacular Archerfish habitat. Thus my photo to the left. Glad to have you as a member.
Stephen

 

[Fresh12]

So you built a very large aquarium. The top edge needs some support to keep the glass from moving. Aquariums have a heavy plastic frame that supports the glass panels top and bottom, with some tanks having corner support as well. Maybe replace the decorative top with something that will support the glass.

That approach should have the desired result without having to add too much more. Plan A is to weld the side pieces of the top trim to the corner section and then silicone it to the top of the glass panes all the way along on both sides - now making it a brace when the silicone has cured.

 

[addy1]

Welcome! Beautiful pond/tank you made.

 

[Mmathis]

Nice pond! Great advice, too!

 

[GBBUDD]

I would use angle iron in stainless I myself would look at a fabricating shop to make it for me because it will be that much more precise . depending on your back walls you may need to wrap all the way around your pond to insure a solid fix . I am going to over step a little here and say while i love your design with the bog in the back section the way you did the entire surround was done if not professionally it certainly looks it. I think your contemporary design should be passed onto the water fall as well. I THINK LIKE THE STACKED URINS they now have stacked walls where the water drops down the wall pretty cool look and would definitely fit your theme.
OUCH i just checked what 15 mm glass is and it's just a half inch yikes. I don't know how many gallons / liters you have there but for a amount of water that you have there i would have looked at a minimum of 3/4" glass and i probably would have bit the bullet and gone a full one inch boxing the seam of the glass vertically and across the top i would say is a must. Is the glass when you look down the side does it have a bow to it ? i know you said you used tough glass but at a half inch for that much water that better be some very strong glass. before you go cray trying to fix things i would suggest a call to an engineer or do some more research 15 mm just seems very thin to me. i believe my 90 gallon fish tank was 1/2'' glass good luck i hope you can make it work it's beautiful well done
'

 

[zeuspaul]

I am not sure I am reading the tables correctly but this https://www.thesprucepets.com/designing-a-glass-aquarium-2924666 glass aquarium design table for a glass fish tank 213 cm long x 61 cm deep with the larger safety factor is 1/2 inch.

 

[GBBUDD]

Wow i never would have thought half inch would do the job to that size. Glad i was wrong it's an amazing set up he has built here

 

[Fresh12]

Well, I've finished the modifications to the pond - so far so good!
Removed the fish into a large tub inside the house with an aerator, drained out the water from the pond and took it all apart. Cleaned off all the old silicone and moved the two glass panes closer together at the corner (4mm gap instead of 10mm that I started with). Then went with Plan-A i.e. welded the side pieces of the top stainless steel trim to the corner section and then siliconed it all to the top of the glass panes on both sides as a brace. After it had all cured, replaced the rocks, refilled with water and then added back the plants and fish.

 

[GBBUDD]

Wish you the best, Hope it does the trick but seeing as it's like what they do in building aqauriums with the top snifter band it sounds like a done deal .