Rimless tanks

[DiscusnAfricans]

How are rimless tanks designed to be structurally sound without framing? Just curious why standard tanks all generally use top and bottom frames if they could be built rimless. The frames are a big deterrent for me in being able to reseal a tank, I've broken the tank trying to remove the framing.

That leads to another question, what is the easiest way to remove a tank frame without damaging the tank? I have a tank that needs a top frame replaced, but I haven't done anything because I'm afraid to do more damage than good. People say its crazy to leave a tank without a center brace in place, but I've seen them hold up fine.

Maybe rimless tanks are smaller and not long by design because of pressure issues, just curious why they're a 'new design' and not the norm.

 

[CSnyder00]

Most rimless tanks I see are acrylic. This is because acrylic seals much stronger than glass. It actually melts/etches the acrylic and bonds the pieces to each other. Most of these are frameless because they can handle the pressure without them. With glass, you are using a silicone bead in between the two pieces to seal it. While this works, it doesn't last nearly as long because over time the shrinking and warping cause the silicone to separate from the glass causing a leak. You aren't bonding two pieces of glass together. This is why you can build frameless acrylic but typically not frameless glass tanks. Seam leaks typically don't happen as often to acrylic unless you move the tank a lot or disturb the bond, or if the bond wasn't perfect to begin with.

 

[DiscusnAfricans]

Gotcha, thanks. I never looked at the rimless tanks close to realize they were acrylic, but that makes more sense.

 

[FishEggs]

Rimless glass tanks need thicker glass to withstand the pressures which equals more cost. The rims and center braces allow thinner glass which equals cheaper costs.

People didn't spend as much money on hobbies/pets q's they do now so tanks needed to be cheaper to sell. Now people spend more money on it and tanks can cost a little more for design astetics. Mostly speculating on the money aspect but that's been my observation.

 

[CichlidAddict]

Most rimless glass tanks are used for aquatic garden, which looks better without rims. It allows lights to shine directly over water without losing intensity through glass lid, and emergedplants grow a lot faster. Without rims, I don't know how the lid sits.

 

[Frank Cowherd]

Glass rimless tanks at least for tanks up to maybe 40 gallons are fine without frames. You can take the frames off any tank up to 40 gallons without a problem.Maybe even larger ones that do not have supports across the tops. I think the frames were either for aesthetics or to cover sharp edges, maybe both. I have used ten and twenty gallon framed tanks without their frames for years in this way. I have had the bottom frame break on a 30 gallon tank and no problem.

BTW, those plastic frames on the framed tanks do not really look like they are bearing any weight, they are not preventing the glass from bulging. The frame does provide a buffer between the glass and the support.

The 65 gallon rimless tank I have was bought for a planted tank. With rimless tanks the manufactures warn that the bottom of the tank must be flat and smooth. Maybe so since an uneven support would add stress to the joints.
Mine has all edges smoothed and the glass is thicker than the old framed type tank. The glue job is very uniform and thin.
I wanted a glass tank so I could use a razor blade to scrape the glass. You cannot do that with an acrylic tank.

 

[bossanova]

I wouldn't remove a frame from any tank, I hear horror stories on YouTube about this. I agree they look much better and more 'euro' without the rims tho. I guess these standard aga tanks were designed with the rim in mind so I'd feel dumb in case of catastrophe...

 

[londonloco]

I have four glass rimless tanks:

12g Mr. Aqua, 36"x8"x9", set up in Sept of 2013. I've moved it 3 times, still holding water, 36" long and no bowing, right now it holds Multi's. Construction is what you would expect from a mass produced tank, thinner glass, (low iron), silicone ok, not great. BUT I love this tank, such a unusual size.

65g 36"x24"x18" green glass (not low iron) rimless custom made by Artfully Acrylic. It was the first and last glass tank Adam has ever made. It's my current reef, set up in August 2013....and it's a friggen tank, 1/2" glass on 5 sides, heavyyyyyy. The sides sit on the bottom glass. I think this tank would withstand a hurricane outside. No bowing.

75g Deep Blue Rimless top, bottom frame, set up in Nov 2013, been moved 4x in the past years, still, no bowing. Nice tank, but not as nicely constructed as the 65g, silicone is ok, but not great.

I just purchased a 80g (48"x24"x16") RR Deep Blue Rimless frag tank to upgrade my reef (want more fish, need the 4 feet width, plus it's been almost 4 years since I've done a build, so ya know.....). Same company as the 75g, and I have to say, the tank is beautiful, silicone is all but perfect, this glass is also not low iron, but I can't tell at all (the 65g def has a green hue when it's empty, filled I can't tell the difference between it and the 75g low iron glass). Not anywhere as heavy as the 65g, but the glass is not as thick either.

I hope I'm not jinxing myself, but I haven't had any problems with any of my rimless tanks, no bowing, no cracks. However, they are not as easy to do a wc with, being rimless, you do have to be careful not to splash water out.

Edit...I forgot ha! I also had a 5g ada 45F set up from 2011 til 2017, it's in storage now. And for a few years I had a 16 gallon IM AIO set up, also in storage. Those tanks are much smaller, but still hold water and have no bowing at all.

 

[finzz]

I've built a few "rimless" tanks in the 30 & 40 gallon range and they've been in service for 15 years or so with no problems. Mine are more for economy than aesthetics: in my fish room all they have to do is be cheap and hold water. The 40s are a cube style and the sides don't bow much at all when full, but the 1/4" glass in a couple of the 30ish long-style tanks bowed out in the center when they were full, so I made center braces out of plexiglass. The tanks are ugly, but the fish don't seem to mind.

 

[AndyNarwhal]

Frames serve a number of purposes.
1. Frames are a jig which makes assembly of the aquariums quicker and easier.
2. Frames lift the bottom glass off the ground. Protects the bottom from sitting on an uneven surface and allows the use of perimeter support stands.
3. Frames offer some structural support which allows thinner glass. Particularly for longer tanks like 55 or larger which have a frame with a center brace.

Frameless glass tanks can be found in all sizes. However, they are more expensive for the following reasons:
1. Glass requires extensive edge grinding and polishing.
2. Taller and longer tanks require thicker glass to keep from bowing/breaking than framed counterparts.
3. Most frameless tanks are made with a floating bottom (where the bottom is actually inside, rather than underneath) the side panels. This is more difficult to assemble.
4. Lids for frameless tanks are generally a piece of glass inset of the side panels with small clips for support.

There are definitely aesthetic considerations that may make one prefer a frameless vs. a framed tank. But from a practical and cost standpoint, the framed tank is superior.