Crack In Bottom Of Tank

[Tropical_Fish]

Just picked up a 2nd hand tank - 30"x12"x12". It looked excellent, just sorting a few bits out for it at home and I noticed a crack on the bottom!

I never noticed the crack when I bought it, I'm sure I didn't do it but wouldn't be able to moan now!

Anyway the crack isn't very big, it's right in the corner. About 2cm from the corner on the long side going to less than 1cm along the shorter side so only a small crack.

Running my finger over the top (inside the tank) I can feel the ridge of the crack but the crack is completely under the sealant.

I've put a couple of inches of water in to see if it came out and it doesn't leak at all but I'm a bit worried about putting 70 litres of water in!

Should I worry? Would you fix it or leave it?

 

[JenCliBee]

Just picked up a 2nd hand tank - 30"x12"x12". It looked excellent, just sorting a few bits out for it at home and I noticed a crack on the bottom!

I never noticed the crack when I bought it, I'm sure I didn't do it but wouldn't be able to moan now!

Anyway the crack isn't very big, it's right in the corner. About 2cm from the corner on the long side going to less than 1cm along the shorter side so only a small crack.

Running my finger over the top (inside the tank) I can feel the ridge of the crack but the crack is completely under the sealant.

I've put a couple of inches of water in to see if it came out and it doesn't leak at all but I'm a bit worried about putting 70 litres of water in!

Should I worry? Would you fix it or leave it?

Any crack is worrying, it could well be superficial however it could gradually get worse... i personally would try and get it repaired but i always look to the catious side just IN CASE!!!

 

[Tropical_Fish]

Just picked up a 2nd hand tank - 30"x12"x12". It looked excellent, just sorting a few bits out for it at home and I noticed a crack on the bottom!

I never noticed the crack when I bought it, I'm sure I didn't do it but wouldn't be able to moan now!

Anyway the crack isn't very big, it's right in the corner. About 2cm from the corner on the long side going to less than 1cm along the shorter side so only a small crack.

Running my finger over the top (inside the tank) I can feel the ridge of the crack but the crack is completely under the sealant.

I've put a couple of inches of water in to see if it came out and it doesn't leak at all but I'm a bit worried about putting 70 litres of water in!

Should I worry? Would you fix it or leave it?

Any crack is worrying, it could well be superficial however it could gradually get worse... i personally would try and get it repaired but i always look to the catious side just IN CASE!!!

I don't think it will get any worse (ie spread) as it goes from one side to the other. My thoughts were to get a small patch of glass a couple of inches square and silicone that over the top in the corner, cover the base with silicone in that corner - stick it down and seal around it - will look a right mess but it will be in the back corner with a load of gravel over the top.

 

[JenCliBee]

I don't think it will get any worse (ie spread) as it goes from one side to the other. My thoughts were to get a small patch of glass a couple of inches square and silicone that over the top in the corner, cover the base with silicone in that corner - stick it down and seal around it - will look a right mess but it will be in the back corner with a load of gravel over the top.

I guess if you think that will work then the only thing you can do is try and hope for the best lol... Good luck and hope it all works out for you

 

[Tropical_Fish]

I don't think it will get any worse (ie spread) as it goes from one side to the other. My thoughts were to get a small patch of glass a couple of inches square and silicone that over the top in the corner, cover the base with silicone in that corner - stick it down and seal around it - will look a right mess but it will be in the back corner with a load of gravel over the top.

I guess if you think that will work then the only thing you can do is try and hope for the best lol... Good luck and hope it all works out for you

I've never done it before so was hoping to get quite a few opinions

 

[razer121]

can i just add.....it will work ive done it although i had a crack go from 1 corner to the other side but at an angle, i used a 5mm thick piece of glass and really silicond the hell out of it lol, the tank is still in my shed now filled with water, its a large tank to so alot of water is on it about 80L if im right...could be wrong but anyway it has been setup in there for about 2 weeks now with no change, after say a month i guess you could say its perfectly safe but then if it last 24hrs chances are its going to be ok

 

[Tropical_Fish]

can i just add.....it will work ive done it although i had a crack go from 1 corner to the other side but at an angle, i used a 5mm thick piece of glass and really silicond the hell out of it lol, the tank is still in my shed now filled with water, its a large tank to so alot of water is on it about 80L if im right...could be wrong but anyway it has been setup in there for about 2 weeks now with no change, after say a month i guess you could say its perfectly safe but then if it last 24hrs chances are its going to be ok

Did you just patch it? Or did you put a sheet the size of the base in?

I think I'm going to price up a sheet of glass which will just fit inside as a second skin, then cover the bottom in silicon, and stick it down, then silicon round the edges and leave for a good few days to cure. That should then be as good as new.

Had a closer look at it just and you can feel the crack on the inside of the tank but you can't feel it underneath.

I've got the tank sitting on some polystyrene and with two inches of water it's been fine but I don't think I dare risk it as it is so a repair will be in order! Are there any particular names for the silicon? I'm guessing clear bath sealant won't be the best stuff!. Just got to decide if a corner patch will be enough?

Any ideas where I could get a patch of glass to go in the corner? If I ask somewhere is it a certain type of glass?

 

[jonp]

any local picture framer should be able to help with glass - they tend to keep a few types normally. not going to try and advise which to use though

 

[rabbut]

Before we jump to any rash decisions, can you post a picture and make dpubly sure it's a crack, not a scratch, or compression fracture (any tank builder will be able to tell from the photo between crach and compression fracture) For a crack, a corner patch may be the best option, for a scratch, let it be. For a compression fracture, a new bace pain will be in order.

For a patch, for a little 70l tank, 2-4mm float/plate will be fine. For a new bace pain, 4-6mm float/plate will be needed, depending on whether or not it's a floating based tank or not (again, will be able to tell via pictures)

All the best
Rabbut

 

[Tropical_Fish]

Before we jump to any rash decisions, can you post a picture and make dpubly sure it's a crack, not a scratch, or compression fracture (any tank builder will be able to tell from the photo between crach and compression fracture) For a crack, a corner patch may be the best option, for a scratch, let it be. For a compression fracture, a new bace pain will be in order.

For a patch, for a little 70l tank, 2-4mm float/plate will be fine. For a new bace pain, 4-6mm float/plate will be needed, depending on whether or not it's a floating based tank or not (again, will be able to tell via pictures)

All the best
Rabbut

Difficult to photograph but managed to get it on one photo. I've found a peice of glass suitable for a repair panel. It's the same thickness as the glass on the tank. I've put a picture of that peice as well.

 

[bae1994]

that sucks i think id stick the glass and test it in the garden

 

[rabbut]

CAn you get an outside view please? It's hard to see the damage properly with one inside photo, but that should leak when full, as the photo does show the crack is not completely covered in silicone and the two parts of the base pain will puch apart when filled creating a leak. A repair is deffinetely needed, the question is is it a new bace job or a nice easy patch

 

[Tropical_Fish]

CAn you get an outside view please? It's hard to see the damage properly with one inside photo, but that should leak when full, as the photo does show the crack is not completely covered in silicone and the two parts of the base pain will puch apart when filled creating a leak. A repair is deffinetely needed, the question is is it a new bace job or a nice easy patch

Can't see anything really from the sides, so it would only be underneath to see from. Can't really get any more pics right now but it looks much the same as above. The crack can be felt from the top with your finger nail but it does feel rubbery over the whole crack. On the underside I can't feel the crack at all with my finger nail.

As I said we tested it with a couple of inches of water, I left it for about 5 hours before draining it out and it didn't leak at all.

I might apply the patch and fill it up in the garage for a week first just in case.

Is the ebay silicon OK? I was going to go with one of the 310ml tubes to go in a gun, cover the bottom of the patch with silicon and press down firmly, and put a weight on it, then seal all around the patch. Does £6 for a tube sound OK?

 

[rabbut]

At £6 a tube, my local LFS is cheaper, and they are considered expencive in my area! Any silicone will do, just so long as it explicitally states that it is aquarium safe

New silicone will not stick to existing cured silicone, so you'll have to cut the silicone seams out of the tank, clean the areas up with a knife and any alcohol based cleaner, before masking taping up any place you don't want silicone and then rubbing down the "soon to be" seam areas with alcohol based cleaner. Now, and only now, do you apply silicone to the repair (and the rest of the tank since that will not have seams any more...). If you don't do all the prep, the silicone will fail inside 18 months, I guarrentee to you So no botching

All the best
Rabbut

 

[Tropical_Fish]

Thanks for the tip about new silicone not sticking to cured silicone. I'd have left it to try and disturb what's already sealed!

So from the description / pics does it sound like I should get away with the patch rather than the replacement bottom?

I'll check out the local shop for silicone, I have a couple of tubes in the house but they don't mention aquariums at all so I wouldn't like to risk it.