Ellie's father is loathe to let us have a new big tank for our goldies because he (understandably) is worried about a large amount of water in the same place leaking everywhere.

How common is it for a tank to leak and what steps can we take to prevent it from happening?

Unfortunately he has a little devil on his shoulder who has horror stories about fish tanks at the ready no matter what we come up with.

Please help us out in getting our goldies a better home!

Thanks,
Pete + Ellie

Gosh I have NEVER had a tank LEAK! That would be terrible! Now on many occasions I have spilled water. Back BP (before Python) I have syphoned water into a bucket & a time or two (?) bumped something & spilled some tank water..............oooouuuu! I have removed a filter for cleaning & a time or two (?)..........spilled water. I have SP........(since Python)................................... A L M O S T over filled a tank (Whew! Had to reverse the Python to take some back out!) And once I was cleaning the gravel with the Python & happened to look over at the sink to see that it was FULL TO THE BRIM! A cloth had fallen into the sink stopping it up.....I NEVER moved that fast in my life!!

A leak in tank....that would be a nightmare! Ouuu, don't even wanna think about that!!

I actually think a leak is pretty rare! Fish keeping is great fun! Tell him to give it a try!!!!

A tank leaking is actually of rather low probablity. Leaking, when it happens, also, usually involves a slow oooooze as opposed to a substantial amount of water. That said, I have heard of an occasional catastrophic break - but I can say, with almost certainty, that some damage was done to the tank prior to its filling - either unknowingly by the person owning the tank, or before the tank was in their possesion.

A tank should never be moved with ANYTHING in it. That means no gravel, no water, no deco. No filter hanging off the back. NOTHING. The tank is held together with a flexible sealant. Flexible is great - but as a tank ages this flexability decreases. Tanks are subject to "shear" damage. Shear damage occurs when the tank is picked up. Picture grabbing your tank by the back panel. That is fine, but the weight of the glass sides pulls on the sealant holding them to the back panel. Flexible, well sealed tank seams will bounce back. Older seams or in the case where the tank has extra weight (gravel, water, filters, etc) it pulls very hard. This can pull the seams loose in places. When the "pull" is released the sealant will settle back in place, but there may be places where it has pulled away from the glass. This is where the "ooozing" leaks will occur.

Anytime a tank twists, or is pulled in any direction other than straight, level and symetrical, there is a possiblity that the sealant will be pulled loose in places. This is the "shear" - like when you twist a plastic package to break it open. Same thing.

The only time you will have catostrophic breakage is in the case of tramatic shock - a blow to the side of the tank. This can occur - causing a crack, that, with the weight of the water, can "blow" out, but cracks are usually visible.

All in all, get a tank either from a reputable source (fish store) or, when you get your tank, do a "leak test". I set the tank on a level floor on a pad of dry newspaper. Then I fill the tank all the way to the brim and let it sit - at least 24 hours. The newspaper will turn dark if any water is on it - a color very easy to spot. This will identify a leak - or even an oooze.

ALways move a tank empty. Always move a tank by supporting the bottom - evenly.

Far more common are the types of leaks stated above. During water changes, it is common to spill water. A tank without a lid can have "spray" from an air bubbler come out. Even a tiny amount will add up. Sometimes a filter is not set correctly. I have a bag tied with a string stuck in a tank's filter - to help cycle a new tank. My cat pulled on the string and left it hanging over the outside of the filter box. This morning, there is a large puddle of water on our oak floors! I have a UV that is leaking - oozing actually. I need to reseal it, also.

As long as your tank is set on a strong, proper support (stand), has had no history of shear damage, and is not in a position to suffer traumatic damage (balls in the house, etc! ) the chances of a large leak are very small.

Thanks for the tips, We are looking at a second hand tank and it has never had water in it apparently (it was first an ex-display model then the chap's situation changed and he no longer could keep the tank to use it)

I was planning on doing a leak test and if necessary resealing the edges but Ellie didn't tell her dad that...

The idea is to make sure the tank is 100% happy before we commit to cycling it because if it's a dud then we can at least sell it on as such and not make too much loss (comes with loads of cool extras)

That was my opinion of the catasrophic leak scenario, only if the glass itself is weakened enough for the weight of the water to break it.

Thanks for the advice and wish me luck with the persuasion