Thoughts on actual tank longevity???

[Magnum Man]

Caffeine thoughts for the day… the bulk of my tanks were purchased in the early 80’s… at a time America was not particularly known for building quality anything… my tanks are all built in, which means some additional support, being caulked along the top, to prevent water / light / critters, from coming into the viewing side… they were all purchased at different times, and I notice a little thickness difference in the glass… all have been leak free, even after going a span of 25 years sitting empty, after being used for several years… my oldest tank, I got used, and went through a building fire, that totaled the building, before it came here…I think the tank is from the late 60’s or early 70’s, and is thick glass, one of probably the 1st plastic frame tanks ( which has all cracked, and fallen away, maybe from the heat of the fire, or just got brittle over time )… these tanks, are all in my basement, so it wouldn’t be a catastrophe, if one started leaking, but I wouldn’t relish cutting one out, and having to replace it… just sitting here pondering how long my tanks will last??? They are all on structural lumber and cement block stands, so all quite stable… I’m surprised the old one still holds water, with no repairs so far… I have an early acrylic 55 gallon, as well, that seems to be holding up pretty good…

 

[Archerfish]

I still have one O'Dell from the early '70's that is leak free. They built those tanks...well, like tanks!

 

[MaloK]

Major factor is the quality of the silicone and the lifespan of what has been used.

We know for a fact that modern silicone have superior properties compared to what was produced in the 70'-80' etc... With superior adhesion, resistance to aging and flexibility.

In the long term, Scale is probably the principal culprit of deterioration, it penetrates the silicone, makes it lose flexibility, becomes brittle and slowly lift it from it's bed.

Then There's UV light that have effects on it, temperature fluctuation during storage and algae growth can also shorten life expectancy.

In service condition, I think that most glass aquarium has at least 10-15 years in the worst condition and up to more than 50-60 in good ones.

 

[Back in the fold]

In fifty nine years I have had only two aquariums ever that needed to be resealed . One was because it was originally sealed with that black tar they used before silicone and the other because I mishandled the aquarium .

 

[GaryE]

My original 20 gallon long, my 16th birthday gift, cracked open 40 years later. The back glass broke.

90% of my tanks were bought before 2006, as my work with the aquarium trade made them a business expense. I wouldn't keep my 120 in the house, and I mistrust it. Eventually, I will start having tank failures.

If I could afford to replace them all, I would. But I can't, so I live dangerously.

The seam splits I have had so far were 2 from a batch I bought on sale. When I took them apart, the silicone was not properly done, and one 75 that just split pretty well randomly, got repaired and split again soon after. It was second hand, I suspect was kept for years on an uneven stand. My even stand probably put pressure on a misshapen frame.

But yes, they have a shelf life, and 1980s ones had great glass but not necessarily as great silicone.

 

[Alice B]

old tanks last longer than new and rectangular longer than hex. most of mine are 20 years old, a couple older, 2 are 3 years old.

 

[Colin_T]

If they use a good quality silicon (not cheap crap from China), the aquariums can last decades and 20-30 years is not uncommon. Back in the 80 and 90s (last century) the aquariums were made locally and were generally good quality, at least around here. Now stuff comes from China (apparently it's cheaper to buy aquariums made in China and ship them here than it is to make them here). But there have been a number of reports about leaking tanks that are only a few years old and they all come from China.

Good silicon, made in your own country, will generally out-perform cheaper lower grade silicon made in some other countries.

The glass also needs to be cleaned properly before the silicon is applied. If the glass has oil or something on it, the silicon is more likely to come away.

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Glass is sometimes called a liquid and does run over time (10+ years). It's not that easy to see on small aquariums and not an issue on small aquariums. But big windows and tall aquariums can get thinner over time. The glass at the top gets thinner as the glass slowly runs down to the bottom. This process weakens the glass and makes it more brittle. If anyone has ever seen a large piece of glass being removed from an old shop window, you will see the top is thinner than the bottom.

 

[GaryE]

The problem with some new Chinese made tanks that I've seen is not any obvious quality of silicone, but rather quantity. It isn't being put everywhere it should be, in the joints. Add the fashion for rimless tanks, and it is cause for concern.

I remember watching the assembly line for 1990s Hagen/Fluval tanks, and they were being really well made. It was efficient speed-wise, but very thorough.

My 40 year old metaframe that spidered out went from the top, which fits with what @Colin_T describes.

My bizarre neighbour has 3 tanks on her deck - a 5, a 10 and a 4 footer. The small tanks have been pulled apart by ice, but the big one is entering its second winter outdoors, still holding water. If she were to offer to sell it to me, I'd see it as panes of glass at this point. It ain't trustworthy. How a tank is treated also matters. Tanks that sit empty and really dry out (without the extreme scenario of them freezing solid) are shakier than ones that stay wet.