Tank Leak! - What Silicone to Use?
 

I just got a call from home, the tank is leaking.

This sounds like a joint between two pieces of glass. If that is the case what silicone should I be using and will it work underwater?

I will pick up this thread when I get home....

silicone won't work under water, you could use underwater epoxy as a temp fix.

drain the tank and seal it but it needs a few days minimun and closer to 2 weeks before i would risk water.

honestly since its leaked once i would drain the tank move the livestock into bins and replace the tank its self.
not worth the risk imo

Silicone won't work underwater. You'll need to drain the tank and remove the current seal and then run a new bead. What size is the tank? Usually it's better just to replace it.

you will need to find some silicon that doesn't have anti-mildew additive.
I don't think there are anymore brands that you can use that you can buy at a hardware or lumber store anymore as they now all have the anti-mildew additve.
you are going to need to get some from a fish store that is specifically designed for aquariums.
ideally, you should redo the whole seam
however, bare minimum - you will have to drain the tank to at least below the leak
I personally would scrap away all the silicon around where it is leaking with a razor blade - don't cut between the glass just the seal bead running along the inside of the tank.
then apply a seal bead along the area.
wait at least 24 hours and refill the tank.
wish I had better news - it is going to be a pain in the a$$
good luck
Neal

Here is a thread on the silicone:

http://www.canreef.com/vbulletin/showthread.php?t=88436

Having resealed tanks several times myself, I would replace the tank given the opportunity.

Dan

sure its the tank? Ask them to investigate further, 99% of the time is is something else associated with the tank such a filtration device of some sort

after reading that link from Fragit Dan
apparently you can get aquarium safe stuff at home hardware
just make sure that it says safe for aquariums
Neal

Thanks to everyone with the prompt responses. I bailed from work to see if I could solve this, more considered about water damage at this stage.

One minor blessing is that this tank is an AIO and the leak appears to be in the rear chambers. That means I should be able to drain the rear chambers only.

I think I have some aquarium silicone around somewhere. I will have to double check on that.

I was mistaken, no silicone at home.

I will head to Home Hardware to see if I can find the silicone that Fragit Dan suggested.

A few of you mentioned replacing the tank. Why? Are repairs not successful?

grant

Yikes Grant,

Worst cast scenario, I'm pretty sure that one of the two reef stores in Kelowna will have some type of silicone.

Have you located that exact spot that it's leaking?

It's more the fact the repairing a tank is a pain and takes time to do properly. If you had a smaller, standard-sized tank, it is usually easier to just spend the extra bit of money and buy a different tank.

A tank leak can cause significantly more damage than what the tank is worth. Tanks usually leak a reason other than one particular defective seam meaning if you repair one leak another could potentially form somewhere else shortly after. Repairs are also difficult and sometimes not possible, just running another bead over the existing one will likely offer a temporary fix.

So depending on the size, value and age of the tank, more often than not it's a better move to replace the tank completely.

Mark:

It is a small leak and of course at the bottom of the tank not the top.

I picked up a tube of Home Hardware brand (aqaurium safe) as mentioned in the previous link.

Yeah, I am more concerned about water damage than condition of the tank and inhabitants. it just happened that my wife was home today. What if this happens when we are both at work or on holiday? Pity the poor tank sitter.

grant

absolutely, all the seams are gonna be the same age so if one leaked another is probably on the way. the cost of a flood is way more then the tank and the loss of livestock is another bad hit, you were lucky this time it was a leak next time could be a full blown blowout,i would look at this as a good time to upgrade:)

make a temporary fix but id look into replacing the tank, i know its an aio so hard and a bit expensive to upgrade but its something i would do fopr sure, plus it would bring some life back into the hobby for you starting over a new tank:) does for me anyways:P

I will have to consider that. I have certainly learned a lot over the past 4 years and may have not gone the AIO tank if I was to start over. Either new tank or getting out of the hobby entirely.
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But back to the repairs: Cut out the offending silicone or apply fresh silicone over it?

If I have to drain the entire set of rear chambers I will apply silicone over the entire old silicone while I am at it.

Silicone doesn't stick to silicone...at least I've never had any luck with that. I would say some removal will be required.

Thanks Mark.

Update: I have drained the rear chambers of water (I new i was saving all of those salt buckets for reason). I discovered the pin hole leak originated at a thin portion of silicone, sort of a dimple where two beads of silicone did not fully meet.

This chamber also held live rock which could have pressed against this dimple and over the span of 4 years finally poked through. That's my current theory anyway. The rest of the bead along that joint seems good (by feel).

So I am thinking that this may not be entirely a failure of the silicone but may have been a very slow mechanical failure?

Is 4 years too early for a silicone failure?

Thoughts?

In my experience, it is. Have you figured out how to seal that joint?

First step is ensuring that I get that chamber totally dry. Then get in there with a scalpel to remove the old silicone, then put down a bead of new silicone.

This will all have to be done by feel since the chamber is too small to look into while I have my hand in there.

Orca underwater Silicone works. Use clams to ease pressure of full tank (compress glass) let sit for 24 hrs, works well have used it several times on old hagen tanks!

Yes, multiple attempts at sealing the leak before I got a dry tank. As mentioned by others, silicone does not stick to cured silicone so you need to cut a lot out and make sure the surfaces are really clean. +1 on the comments regarding the other seams potentially being ready to go as well. I had a stand go on a 75G FOWLR tank in 1997... final insurance tally was $66K. I would expect more than four years out of a tank so there might be other issues with it. If a leak isn't going to cause a lot of damage to your house you might want to risk it, but perhaps not. The tanks I have resealed are on a cement floor in my basement so no real risk to damage the house,
Dan

We have Orca underwater glue available, it works great.

http://www.royalaquariums.ca/p/464/o...ter-glue-black

This stuff is pretty good for underwater glue, but not for repairing a blown seal on a tank. If a seam is leaking, it needs to be repaired properly.

You need to cut the silicone away and clean it with alcohol to completely dry the surface and remove the water that is in the joint as well. Next, fill the joint but ensure there are no air bubbles whatsoever. It is best to do with 2 people. 1 person filling and the other person watching from the outside to ensure no air bubbles are present while caulking. Use a silicone caulking applicator to push the silicone in place and create a nice clean bead. Wait a good 3 days before putting water back into the tank.

Honestly, a new tank is all ways a better option than trying to do repairs...