Mr. Saltwater Tank

Terrible Advice Tuesdays: What To Watch For If You Have A Glass Aquarium


Terrible Advice Tuesdays (T.A.Tues): Any saltwater tank made of glass will fail within 3 years due to the drying out of the silicone seals.

The rest of the story: The idea of all glass tanks failing within 3 years is absurd. First, the silicone is constantly submerged in water, which leaves me wondering how it can dry out. Perhaps the person giving this bad advice was suggesting that there is some kind of chemical reaction between the saltwater and the silicone that ages the silicone prematurely. Even if this was the case, then aquarium makers would have switched to a different sealing compound years ago.

Second, if glass tanks fail within 3 years, then no glass tank maker would be in business as explained by a professional aquarium builder:

“If the idea that saltwater immediately starts drying out silicone was true, then the amount of failures of these tanks would be astronomical and any tank maker would be out of business. I’ve personally witnessed several old Oceanic tanks that I built 15-20 years ago still going strong today.”

– Jerry Acuff, Planet Aquariums, 20 year veteran of building saltwater tanks

If you have a glass tank, don’t worry about your tank failing within 3 years. Do keep an eye out for the silicone getting worn off by algae scrapers or your unsteady hand if you are scraping your glass with a metal blade.

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Comments for this article (18)

  • Mark H. says:

    I have several tanks that have been in service for 15+ years that are still going strong, I can see the silicone drying out and failing if the tank has set empty for years. 🙂

  • Nikolaus says:

    I heard this same advise 30 years ago. From what I understand, it comes from noobs buying old used tanks, not knowing how to inspect the seals. The silicone would degrade over time (and use) then sit empty for years. Noob sees it at a cheap price so they buy it, in 3 years it pops.

  • Patrick says:

    I have a 70 gallon tank that has had salt water in it from 1968-2000 (moved twice) and then from 2005-present. It has never been resealed. Holding strong!

  • Tim K says:

    I have a glass Oceanic that is almost 14 years old still going strong. I had the tank setup for about 5 years, then it sat in storage for 6 years (between moving and having a couple kids), then set it up again 3 years ago after my kids got me back into the hobby after visiting the Baltimore Aquarium. I’m going to be shutting it down this year to move everything into my new 235 gallon build I am working on now (also glass).

  • Brian says:

    Someting worth metioning here is the stand…. An aquarium is only as good as the stand its sitting on. Any flex or uneveness will short live a tank.

    We purchased a 120g tank from LFS. When they brought the stand out to the truck I said this can’t be the right stand, the insisted it would be fine. Built of pressboard and twist tight connectors, I told them if they are going to guarante it then fine we’ll take it.

    It failed 6 months later, the bottom fell down on Christmas eve no less. It didn’t flood all at once, but leaked very fast. I made a gutter system around the bottom of the tank that fed into a 5 gallon bucket and put a return pump in the bucket back into the tank till the store open.

    They replaced everything, including the proper stand….

    Cheers

  • Greg says:

    I bought a new 55 gal aqueon and set it up for two years, saltwater. Then it went into storage for the next 20 years and was moved 7 times. Set it up a year ago & no problems yet.

  • Vic Brincat says:

    My 130g glass aquarium is in it’s 18th year of operation.
    It will be retiring this year (moving up to 370g). It has never leaked.
    It is sitting on a wooden stand that was not level and isn’t even straight or flat because I built it hurriedly on the day I moved in the house.
    The only problem is that after 18 years, there are a few scratches on the glass.

  • nicholas says:

    The German company Hagen that make tanks under the name “Fluval” say you should replace your tank every 8 years!!. Their tanks are made for fresh water, but as they say salt water does not effect galss or silicone, it makes no difference.

  • Russ says:

    My little “traveling” glass tank story….my dear friend bought a glass/silicone 90 gallon tank from a LFS in 1977. He had it running fresh water until he sold it to me in 1987. I set it up withing a couple days and kept it running with fresh water until 1989. Broke it down and placed it with three people, it was so heavy, in storage until 1992 and started it back up with salt water. Broke it down again in 1993, put it in the garage and set up up again with fresh water after a move in 1995. Moved again in 2001, placed it in storage until I gave it to a friend in 2003. He set it up and kept it running with fresh water until 2009. He Broke it down, put it in storage until 2010, for which his son set it up salt water and it has been running ever since. Never a problem, never a leak. Did we get lucky, I would assume, but to this day, it is running without a leak, same 2×4 stand too. One note, the glass was thick, this tank is a tank…….thicker than my glass/silicon 150 mixed reef now and my custom built by myself, glass/silicon 60 sump. (I would bet you couldn’t purchase that type of silicon now on my traveling tank)

  • Darren Thomas says:

    Had a 16yr old rimless 90g, glass was sooo thick. Used it for everything freshwater, saltwater, and even reptiles (no water, so it got nice and dry). After 16 years I noticed (while it was being used as a reef tank) that the seams were peeling apart on all sides. Needless to say I was nervous but not panicked. When I finally replaced it, I thought I’d tear it down and use the panes eventually. Even with a utility knife I could not get one single pane apart. That was some strong silicone.

  • kevin talbert says:

    My all glass tank busted last year, the bottom fell out, ouch! The tank was in storage for a couple of years, that’s where it probably dried out. What a mess…..

  • Matt says:

    I set up a fresh water tank for a family friend 19 years ago … it’s still going… a bit scratched but still there on its metal frame. Enough said 🙂

  • Mohamed Alnuaimi says:

    My 2.6, 350g 1.8 years old leaked last month and I replaced it with new one. The reason was bad silicon glue cheap one, the guy how build it for me used cheap glue. There are hundreds of Silicon glues in the market. Make sure you use the right one.

  • Damion says:

    Funny timing of this. My 8 year old 55gal just had the back glass shatter and empty its contents into my living room 3 weeks ago. I managed to save all the fish, but lost all the coral. (Saved 3 rose bubbles too) We now have a 90 gal and will be stocking up soon. Thanks for what you do Mark, Its much appreciated.

  • Coach T says:

    I have always had glass aquariums and have been in the hobby for 25 years. 1 tank out of maybe 10 to 12 of the ones I have owned leaked. the one that leaked was a 10 gallon and it’s probably because I was young and did something too rambunctious with it. I actually had a 55 gallon and the center brace snapped because of poor handling on my part…. The tank bowed out in the center the glass was bending out maybe an extra inch and it never broke nor did the silicone leak

  • DeeFromBrooklyn says:

    I bought my tank over 17 years ago and have houses everything from Oscars to my current reef inhabitants. Now let’s talk stands which probable are more likely to rust out or fail. Especially any stand made of laminant which are quite widely sold these days. What do you think Mark?

  • Dee…stands are usually the weakest link. The funny part is if you don’t put the tank on the manufacturer’s stand, then the warranty is void. Yet a lot of the stands are horrible!

  • Rob says:

    I think acrylic makers started that rumor years ago… although when buying a used tank, I’d always want to see it hold water before taking it home. 😉

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