Tank Leak

fish flipper

fish flipper

New member
I have a 42 gallon hex tank that I bought from craigslist. The silicone was peeling so I scraped it all off and re-siliconed it. I tested it with water and found no leaks. I set it up in my house and put rock in the tank to cure. After a month with the whole system running with rock and sump fully set up I came home to the tank leaking and about 15 gallons of water on the floor. I drained the tank and took the rock out. If I silicone it again how can I be sure it won't leak again? Should I remove the silicone from that corner and seal it again or can I just silicone on top of what's there? Why did it take so long to start leaking? Is there a better way to test for leaks to prevent this from happening again?
 
When you said you scarped the silicone off did you remove the silicone on the inside (overlapping the glass panes) or the silicone joining the glass panes together?
 
If you took off silicone anywhere you would need to redo the entire tanks silicone in one shot. Silicone will not adhere to old silicone once dried. Also, what type of silicone did you use?
 
BrandonFlorida said:
If you took off silicone anywhere you would need to redo the entire tanks silicone in one shot. Silicone will not adhere to old silicone once dried. Also, what type of silicone did you use?
Click to expand...

+1

Also, you need to make sure you scrape off every little bit of old silicone (which is difficult to do - a lot of manual labour) or it'll not work properly.
 
This is the silicone I used. When I took the silicone off I did completely remove all of it from all seals in the tank and then put fresh silicone on the whole thing.

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Next time remove ALL of it, and use Momentive RTV 108. If you look up the data on it, the 108 is much stronger.

Also, the internal seals are just for aesthetics and to protect the glass-to-glass seals. The ones that hold your tank together are between the panes of glass, not the internals.

Sorry you are having trouble with this.
 
So does that mean I have to take all the silicone off the inside and the silicone between the panes? That would mean taking the entire tank apart down to just the panes of glass. If i have to do that I wouldn't even know where to start to put it back together. Hardly seems worth it. I even spent the last few months building a custom stand and canopy for it.
 
you're going to want to remove that silicone anyways, silicone II has mold inhibitors which are bad for any type of fish tank. RTV 100 series is the best way to go, its much stronger than GE silicone and i'd trust it better for holding the tanks glass together.


but yes, you will need to basically strip it down to panes of glass to get it to the point of starting with all fresh silicone between glass, etc...
 
GE type II is not suitable for aquariums.

GE type I is what you want. It's harder to find but there are thousands of tank built with it.

GE All Purpose Silicone I 100% silicone is compliant for incidental food contact under FDA 21 CFR177.2600 "Rubber articles intended for repeated use."
 
Ugh....thanks for the help guys, not what I wanted to hear but I appreciate the info.

Has anyone done this before? Are there any special tools that I would need to do this? Would I use the top and bottom plastic pieces as a guide to make sure the panels are straight?
 
I hate to be the bearer of bad news, but I would abandon this tank. Sell it as a reptile tank.

Rebuilding a standard rectangular/square tank is hard enough, a hexagon is NOT for the typical DIY'er. As mentioned, the structural seam of the tank has been compromised. The only way to truly fix this is to completely break down the panes of glass, remove all of the old silicone and then rebuild it. A hexagon adds a ton of complexity to the rebuild simply due to all of the panes that must be lined up properly and assembled fast before the silicone begins to cure (less than 10 minutes).
 
CuzzA said:
I hate to be the bearer of bad news, but I would abandon this tank. Sell it as a reptile tank.

Rebuilding a standard rectangular/square tank is hard enough, a hexagon is NOT for the typical DIY'er. As mentioned, the structural seam of the tank has been compromised. The only way to truly fix this is to completely break down the panes of glass, remove all of the old silicone and then rebuild it. A hexagon adds a ton of complexity to the rebuild simply due to all of the panes that must be lined up properly and assembled fast before the silicone begins to cure (less than 10 minutes).
Click to expand...


+1 ....I would have a hard time trusting the tank. You'll end up putting $$$$ of corals at risk to save a couple hundred.
 
Thanks for the help guys. I actually found the same tank on Craigslist for $40 but it has a small chip in the corner of the tank. He shows it with water in it and no leaks. He claims to have been using it with fish in it for a year now with no problems. What do you guys think of it? If it's just a small chip on the outside it should be fine, right?
 
fish flipper said:
Thanks for the help guys. I actually found the same tank on Craigslist for $40 but it has a small chip in the corner of the tank. He shows it with water in it and no leaks. He claims to have been using it with fish in it for a year now with no problems. What do you guys think of it? If it's just a small chip on the outside it should be fine, right?
Click to expand...

Personal opinion, I wouldn't risk it. In the long run the tank is actually one of the cheaper pieces of a reef aquarium. Id hold out for a used one in perfect condition or buy a new one.
 
The issue with that is they don't make the tank anymore or any with the same foot print. I built a custom stand and canopy for it specifically for this tank.
 
fish flipper said:
The issue with that is they don't make the tank anymore or any with the same foot print. I built a custom stand and canopy for it specifically for this tank.
Click to expand...

man you are in a tight place... maybe finding a tank builder within driving distance and having them rebuild it for you?
 
I wouldn't touch it at all with a good size chip like that... eventually that tank is going to leak from that spot... it may be 10 years or it may be 10 days, just too much of a gamble considering the cost of livestock and the headache of cleaning up a tank flood... Granted that is my personal opinion, I would keep looking for a chip free one, look into having yours rebuilt, or cut losses and move onto another dimension tank.
 
I wouldn't buy it. I'm sorry man. Sell the whole thing as a nice reptile tank. Maybe you can recoup or even break even.
 
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