Used tank and tank storage questions

[GalaxyBenny]

Hi all-

I'm looking at purchasing a used tank from a fellow reefer in my area, but curious for some expert advice before I pull the trigger. A little background to help with the questions. The tank is a ~15 year old rimmed Oceanic 120 fat boy (4x2x2). The tank has been in constant use up to a few weeks ago, filled with water and without any leaks. The 120 FB tank size is what I've been dreaming about for an upgrade, but in all honestly I am NOT ready to actually upgrade at this moment. Because it's a local deal though, it's a fantastic price on the setup, so I'm contemplating whether to purchase it and just keep it in storage until the time that I AM ready for the upgrade. That being said, here are the questions:

1) How concerned should a person be looking at a used tank that has recently been filled with water and didn't have any leaks? Meaning, do the seals just "wear out" over time (due to UV exposure from the sun/reef tank lights) such that after 15-20 years you need to be thinking about breaking down the entire tank and getting all the seams re-sealed (including between the panels). It's my understand that Oceanic used to make a really great tank, so I don't know if that would influence your thoughts on whether or not I should be factoring in resealing costs/time in my decision process.

2) As mentioned above, I'm not actually looking to upgrade right at this moment, so if I moved forward I would be cleaning the tank up and then putting it in storage in the studio space above my garage. It would sit in a semi-conditioned space (doesn't freeze, doesn't get to attic temperatures), but it would definitely see more temperature swings than inside a home itself. Do I run the risk of ruining the seals by leaving it dry for 1-2 years until it was time for the upgrade?

As always, I very much appreciate all your insights. Thanks in advance,

David

 

[KrisReef]

Silicone is fairly durable and should be able to handle storage you described. I don’t know what the tank manufacturer would say for seam life expectancy and I would not set up an old glass tank myself because I don’t trust silicone to last forever ( vs an acrylic bonded seam box.)
The stress of 15 years constant water pressure upon the silicone bond would make me want to spring for a new tank vs used but that is something you need to figure out if you can sleep well knowing what you are doing.
I understand great deals but I’m not comfortable with silicone so I wanted to give you my thoughts for your consideration.

 

[GalaxyBenny]

Got it, thanks much. Do you guys know if a tank that is 15 years old still used silicone to seal the actual glass to each other) like the small seam itself, not the inner bead? Or was it a glue? The reason I ask is that it's my understanding that you can fairly easily re-seal the inner bead (scraping out, etc. etc.), but that it can still leave a bad seal because that new silicone won't attach well to the old stuff that is in the seam itself. BUT if the seam is not silicone, but a glue, I guess that changes things. Thoughts?

 

[DCR]

The old Oceanic tanks were more leak-proof than most any tank built today. I wish they were still around. I never heard of one developing a leak. I used some 75's and a 110 gal tank that were 40 years old. I would not worry about a 15 year old Oceanic 120. They used heavy glass, a strong wide center brace and good quality silicone. I would leave the old seal. The excess part of the seal does not provide any real strength. What matters is the silicone between the glass. You can remove it and re-apply a bead for cosmetic reasons if you like but I think you do more risk of damaging the seal between the glass panes in doing so.

 

[GalaxyBenny]

Got it, that's extremely helpful. Thanks for your advice. I will definitely check out the tank then, especially because the current owner has been using it without issues for it's entire life, it seems like that is a good sign that he "has history."

Do you have any comments on whether or not I would "ruin" the tank by leaving it empty for months/years?

 

[DCR]

Leaving dry for months will not affect the integrity. I left some dry for over ten years and then refilled with no issue. I would keep it sheltered and not exposed to UV from the sun.

The Oceanic tanks had a very large center brace on the 120 gal. It adds a lot of strength but is a bit of a nuisance when working on it and reduces some of the light penetration. I assume you are OK with it

 

[GalaxyBenny]

Yea, I know that support is there. I'm still thinking through how much I "care". The tank seems like a really great deal ($100 for the tank, stand, sump tank, etc.). So I'm debating how much I can "deal with" for the money. But most importantly, I don't want to buy $100 tank which would end up being substantially more expensive if it leaks. But you've alleviated many of those worries, which is much appreciated.

 

[DCR]

I would certainly take it for $100. It should be a really solid tank and I think it is about the perfect size for a reef tank. A comparable tank is going to cost 10X. I find the wide center braces to be a bit of a pain at times to reach around, but it does not really affect the performance of the tank IMO.

 

[CoralB]

I had a 150 gal tank that I broke down in 2002 when I moved . And sold it back to the pet shop that I bought it for trade . He informed a year later that as soon as he put water in it , the bottom fell out . He said he didn’t say anything because he wanted to keep me as a customer and the stand was custom and in great shape . Said it made up for the tank which he said he had it resealed . I only had this tank set up for three years but I kept the temperature at 85-86 for discus . That was with water in it . Since that incident I would be wary of storing a tank in a non temperature control place . The tanks I use now have much thicker custom glass and I’ve been led to believe that the black glue they use now is much stronger . Plus I keep the temp at only 78 degrees . Personally if I was making the choice and Money wasn’t the issue I would go new . Although some say used tanks might be fine and that might be true , I have to think and have piece of mind that the tank won’t burst or leak especially if no one is home to act swiftly. I have more to lose than just the tank and the inhabitants. I have when I was a young man set up used tanks but they were much smaller tanks and back then I never worried about the consequences of a leak . Never really crossed my mind until I started setting up the much larger tanks . Just my thought . Good luck !!!

 

[Freenow54]

Was told not to leave tank empty by guy at LFS. I had one that was 5 months old. I filled it with fresh water tap fine, and just put a hang on back filter on it. it was fine left it that way for 8 more months saving for the day. However tanks are cheap so why bother

 

[NowGlazeIT]

If your worried about silicone drying out you can always lubricate it with Dow 111. I do this on the outside of my tank where the seal between panes are exposed. Nobody like dry joints….
As for the condition of those seams after 15 years. I would definitely consider cutting the old silicone out and laying on another bead on the inside corners.