# 50g Tank Leaks like a sieve



## johnnymax (May 22, 2019)

Well, I picked up a tank and stand I saw on the side of the road. I assumed it leaked (No cracks).
I thought I could tell where is was leaking so I cleaned that section and sealed it with aquarium silicon. 
NOPE! I should have know. It is never easy.
So, I am going to order a large tube that will fit in my caulk gun.
I am going to cut all the silicon off with a razor, clean the surfaces with acetone and just recaulk the whole tank.
Any tips and advice are welcomed.
Worst case, I put it in the livingroom and it starts to leaks and the wife ruins my happiness for an unknown period of time.


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## johnnymax (May 22, 2019)

I have never resealed a tank before. Is it pretty much straight forward? 
Remove old silicone, clean and reseal?


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## nodima (Oct 3, 2002)

That is pretty much it. Do some searching, as there are a lot of little tricks to the process. As with most projects, the more time you spend in preparation, the better the results. Taping off the areas along the seams and smoothing out the silicone with a spoon are two tricks I've seen mentioned. And you must get all the old silicone off, as new will not stick to old.


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## Old Newbie (Feb 18, 2017)

johnnymax said:


> I have never resealed a tank before. Is it pretty much straight forward?
> Remove old silicone, clean and reseal?


No need to special order silicon; just go to your local hardware store and get GE Window and Door 100% Silicon. Any 100% silicon will work, just stay away from anything that is mold/mildew resistant.


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## ken31cay (Oct 9, 2018)

I use Dap All Purpose which is 'Aquarium Safe', for use inside my tanks. Though as Old Newbie mentioned above, any 100% Silicone with no other additives will work too. Don't go by the product's drying time instructions, wait longer for it to completely dry. Wait until you can smell no trace of acetic acid, then it's safe for even the most delicate fish.
https://www.homedepot.com/p/DAP-Silicon ... /100128841


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## DJRansome (Oct 29, 2005)

Pay close attention to advertising about mold and mildew. The product will still say 100% silicone. I killed off my 125G by using something with "bioguard" or something like that. Now I pay more for the Aqueon product...worth a couple of dollars.


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## Kipnlilo (Feb 23, 2018)

If you do get GE, Get GE 1. GE 2 has the mold/mildew in it.


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## johnnymax (May 22, 2019)

WOW! Thanks for the tips!
100% Silicon. 
No mold killing chemicals.
Tape up.
Clean GOOD.
SPOON!


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## noddy (Nov 20, 2006)

johnnymax said:


> WOW! Thanks for the tips!
> 100% Silicon.
> No mold killing chemicals.
> Tape up.
> ...


I think G.E have a window and door and a bath and kitchen. The bath and kitchen is the one with mold inhibitors.

Whether you use a spoon or your finger, a good tip is to dip (finger or spoon) into a bowl of warm, soapy water. The silicone is less likely to stick to it.


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## Ronzo (Sep 8, 2013)

jb;

...and the cleaning part cannot be overemphasized...when you (think you) are done cleaning the old silicon and biofilms (which stick tenaciously to the glass), I'd repeat the process once or twice...use razor blades, non-scratching abrasives, completely evaporating solvents like acetone, and lots of elbow grease...

Cheers


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## johnnymax (May 22, 2019)

I read where someone resealed a tank and it pulled apart. They were told that they needed to take the tank completely apart and reassemble it, or it won't hold. I hope that it not necessary! Is it?


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## Ronzo (Sep 8, 2013)

JM;

Resealing means just that...it does _not_ mean disassembling, and reconstructing...when using the razor blade to separate old silicon from glass, I cut down from the side which butts into the other pane on the corner, this keeps blade from getting between the joint to separate them (I only want to remove sealing filet, not the glued butt joint!), then come in on the other pane up to the cut only (no deeper), and then proceed with supercleaning...but in your case, since you have a leak(s), if you locate the compromised glueing joint area(s), I would go deeper between the panes (only) in those area(s) to attack the compromise allowing the leak(s)...

Then, when applying the new sealant, I'd start at those "special area(s)" to make sure sealant got into them to address the leak(s), then (immediately after and before RTV skins over) do the rest of the joints...

Cheers


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## BillD (May 17, 2005)

I would add, buy a big pack of single edged blades. You will use more of them than you think, as they dull quickly. When you are sure you have gotten it all, take a new blade and go over it again. Also, get the tank clean before starting. Remove any residues such as mineral deposits and bio film. It is much easier to do it first. 
Mcdaphnia posted a great idea a while back for those who are inexperienced or uncomfortable using a caulking gun. Practice on a cardboard box using the cheapest caulk you can find to help determine the size of bead and the feel for applying it. Do a dry run to determine the easiest and fastest way to apply the silicone. Sometimes this means rolling the tank to get easier access. With a large, heavy tank, having an assistant to roll the tank is necessary.
Lastly, the tendency is to apply a much bigger bead than necessary. What then happens, is you get a blob forming when you smooth, that gets bigger the farther you go.


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## Oscar6 (Aug 4, 2017)

All good tips above. Absolute sterilized glass is the key. When you think its perfect, hit it again with acetone. Extended cure time also a big help. Wait a week, even on a small 50g job. I recently resealed my 7ft 265g. More Marineland junk, dont get me started,lol. I had to get in it to both clean and seal. I let it cure a month. Overkill? Perhaps, but a one time endeavor, I needed extra assurance. Leak discovered New Years day, this year. Fish back in Mar 17. I am confident it will hold many more yrs. I have done many tanks over the yrs, only one failure, and I never could figure why. Sold it cheap to a reptile keeper.


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