Replacing silicone in a 200g

Maggie321 · Apr 30, 2018

I have a 200g (I think its actually a 210) that I am attempting to get up and running in the next few months. The silicone is old, ratty and gross. I would like to reseal but am unsure if I am capable. It currently does not leak but it's been dry for about a year so I don't know if it's changed or not. Normally I am a pretty decent DIYer, so I'm confident I can do it with a bit of direction. I would like to use black because I think it's more attractive and hides flaws better, but can that be bad too? I was thinking I should reseal soon so it can have plenty of time to cure while I finish the other projects (new wood floor, and the tank stand mainly) then when I get ready to do the plumbing, I could drill it then. But, any way is this realistic? Or am I just going to ruin the tank?

Pife · Apr 30, 2018

Maggie321 said:
I have a 200g (I think its actually a 210) that I am attempting to get up and running in the next few months. The silicone is old, ratty and gross. I would like to reseal but am unsure if I am capable. It currently does not leak but it's been dry for about a year so I don't know if it's changed or not. Normally I am a pretty decent DIYer, so I'm confident I can do it with a bit of direction. I would like to use black because I think it's more attractive and hides flaws better, but can that be bad too? I was thinking I should reseal soon so it can have plenty of time to cure while I finish the other projects (new wood floor, and the tank stand mainly) then when I get ready to do the plumbing, I could drill it then. But, any way is this realistic? Or am I just going to ruin the tank?

I wouldn't do it unless you've worked on resealing smaller aquariums. That means you need to completely tear it apart every pane of Glass clean all silicone off of every seam and then reapply silicone and keep everything square and stable and no air bubbles. It is almost impossible without the right equipment.

2clown · May 7, 2018

Completely realistic. Black is really nice. You only need to remove the interior seal. Unless you want to completely rebuild the tank. I would go with RTV 103 or 108. Good luck

Maggie321 · May 7, 2018

2clown said:
Completely realistic. Black is really nice. You only need to remove the interior seal. Unless you want to completely rebuild the tank. I would go with RTV 103 or 108. Good luck

Why do you say I only need to replace interior seal and everyone else is saying complete rebuild? I am leaning toward not doing it, as I looked again the other day and I think my imagination got carried away. It's not as bad as I "remembered" but I would still like to pretty it up. I will be installing new hardwood floors before the tank goes in so I don't want to ruin them by having a saltwater tank bust, you know?

Sleepydoc · May 8, 2018

Maggie321 said:
Why do you say I only need to replace interior seal and everyone else is saying complete rebuild? I am leaning toward not doing it, as I looked again the other day and I think my imagination got carried away. It's not as bad as I "remembered" but I would still like to pretty it up. I will be installing new hardwood floors before the tank goes in so I don't want to ruin them by having a saltwater tank bust, you know?

I agree with 2 clown. Tanks have a structural seam of silicone that bonds and seals the panes of glass, and an inner seal (the fillets in the corners.) If the tank doesn't leak then, the structural seams should be ok. Replacing the inner seal is definitely doable for someone who's reasonably handy.

I'd start out by filling the tank to make sure it's still watertight - if it leaks then you're looking at a complete rebuild, and that's an entirely different game. Once you have it filled, you can decide if you want to replace the inner seals or not. The RTV silicone Clown suggested is a good choice.

mfinn · May 8, 2018

As already mentioned, I would fill the tank with freshwater and let it sit for a week or two ( with a heater ) to make sure it doesn't leak at all.
If it even has a tiny leak, the whole tank and all the panes of glass needs to be taken apart and redone from scratch.