Sealing used aquarium

Kyle Stephens · Feb 3, 2019

hi there I’m new to the page. I just bought a used 210 gal. Aquarium and was wanting some advice. The silacone on the one inside corner of the tank is pretty beat up looks like someone used a scraper to remove the algae.
My question is can I just replace that one corner or do I need to reseal the hole tank? It holds water just fine it’s more of a visual thang for me. I’m just a little ocd and would like it to look nice when I start setting it up.

BestMomEver · Feb 3, 2019

If it’s holding water, I would just reinforce it. But... I am definitely not an expert. Someone will come along in a few!

Lowell Lemon · Feb 3, 2019

You can clean it up with a razor blade and reseal it. However if you are OCD you may not stop there and end up doing the whole talk lol. If you do attempt a reseal make sure you use the best silicone that is manufactured for aquarium use. But some would say if it ain't broke don't fix it as it might create a leak. Something to consider.

crusso1993 · Feb 3, 2019

Not sure what you'll decide to do. However, if you do choose to reseal the tank, I strongly recommend using this silicone. Considered by many to be the best available silicone. Also, the price is really good in the second link.

https://www.americansealantsinc.com/asi-aquarium-sealant/

https://www.bestmaterials.com/detail.aspx?ID=19108

cracker · Feb 3, 2019

So have you done a leak test? is the corner in question front of back? if it's not leaking,

Kyle Stephens · Feb 3, 2019

No it’s not leaky. It’s just my ocd kicking in and would like everything perfect before I start to do the build. I just don’t want to half to worry about it maybe leaking down the road. Thanks for the help I decided to order the asi aquarium silicon and just reseal the inside to make sure it will last me. I’m super exited to start tearing down my 125 gal and put up my 210 gal.

Jacked Reefer · Feb 3, 2019

I would just do it right the first time and reaseal the whole thing. You never know if there is invisible problems. And don’t listen to the people telling you what silicone to use. Reasealing does not effect structural integrity enough to use hardcore silicones.

crusso1993 · Feb 3, 2019

Kayden Hutchings said:
I would just do it right the first time and reaseal the whole thing. You never know if there is invisible problems. And don’t listen to the people telling you what silicone to use. Reasealing does not effect structural integrity enough to use hardcore silicones.

Kyle Stephens said:
No it’s not leaky. It’s just my ocd kicking in and would like everything perfect before I start to do the build. I just don’t want to half to worry about it maybe leaking down the road. Thanks for the help I decided to order the asi aquarium silicon and just reseal the inside to make sure it will last me. I’m super exited to start tearing down my 125 gal and put up my 210 gal.

Regardless of structural integrity, you want to use a silicone that is aquarium safe. Most silicones available are not reef safe. As a matter of fact, you will not find a reef safe silicone available at any big box store. Many people will tell you that GE012A (aka GE 1), which contains Octamethylcyclotetrasiloxane (aka D4) is safe to use. GE 1 or GE012A has D4 at 1-5% by weight. Studies on D4 have shown extremely low quantities (we are talking µg / liter) can limit growth, reproduction, and decrease health in fish and it isn't good for us either. It also bioaccumulates. Once these silicones cure the risk is lessened, but D4 DOES still leach into water. Additionally, GE1 is not designed to be used under constant water submersion.

Good luck with the reseal!

Larry L · Feb 3, 2019

Kyle Stephens said:
I just don’t want to half to worry about it maybe leaking down the road. Thanks for the help I decided to order the asi aquarium silicon and just reseal the inside to make sure it will last me.

FWIW I don't think the silicone in the inside corners of the seams adds much structural strength, I think it's mainly the silicone that's actually between the edges of the sheets of glass that holds everything together, and you can't reseal that without taking things apart.

PghReef · Feb 3, 2019

I had a similar issue where a scraper beat up the silicone and it was looking pretty thin on a 46 bow front. Passed the leak test fine and I didn't want to reseal the whole tank so I just used the silicone suggested above to reinforce the corners and make clear thicker silicone seems.

I doubt it added any structural integrity but as mentioned I believe the strength comes from the silicone in between the glass panes and not the corner bead.but it looks better and provides a little protection for the structural silicone underneath.

lapin · Feb 3, 2019

Clean that inside corner and reapply some silicone so it matches the other side. You can then be happy. Its not needed but will look great.

RStanley · Feb 3, 2019

I understand the OCD when I got my 72 bowfront the seams were beat up. I cleaned out all the old silicone, wiped it down with rubbing alcohol, used masking tape for strait lines, cut the corner off a used gift card as a scraper, and re sealed the whole tank. It had black silicone so the lines are noticeable too me and if they weren’t strait it would have bugged the hell out of me!

Erica-Renee · Feb 3, 2019

Just went thru this , But i actually had a leak..

Recommended
Best practice is to tear the whole tank down , Scrape all sealant with razor blade then get residue off with acetone . Reassemble the tank with RTV Or similar HIGH BOND Adhesive Silicone.. I Went this rout because my tank was 25 years old. which is about the life of the seams so i have read .

Not so recommended but its better then doing nothing..
Now if you look between the panes of glass and there is NO Air bubbles, or discoloration , You can Cut out whats pealing (by the way crabs do this not just razor blades) Reseal the tank and let it cure for about a week before you put it into use.. RTV will stick to cured silicone but its not as good of a bond as original....

The new Adhesive silicone is much better then what was used when our tanks were made back then. I have tested it with bonding to old silicone and it acutally does Quite well.Other say DO not do this just because other people tell them not to ..

Clean Clean Clean is the key...

Good Luck