ok so my tank started a leak quite awhile back. i noticed a few drips coming from the top back corner on a hex tank. i siliconed around the whole thing and in every seem. it seemed to help for a very long time. then one day it was wet around the bottom in front. but only for a few days. then it wouldnt then it would. off and on for awhile then it stopped completely for almost threee months. and now its doing it again but now every day.

can someone please tell me wat is the cause of this and if there is anything i can do to fix the issue? my neighbor thought maybe it had to do with heating and expansion so i turn the heat down but this did not help at all. i cant afford a new tank, so if i cant fix the problem im afraid im going to have to get rid of my oscar and the two plecostemous. i just have a bad fear that one day ima come home from work and have a really saturated floor with 3 dead fish and a hugh mess.

Hey jess this sounds the same as an issue I had with one of my Juwel tanks.
It used to leak a very small amount from the top and run down the glass on the outside and leave a lime scale mark after a while.
I believe its due to the lights causing condensation and this goes between the plastic rim and the glass and drops down the outside.
Its nothing to worry about and does not require buying a new tank....that's if im right.

Hope this helps

i had my hexagon start to leak a little bit, but within an hour it looked like this:




Within 2 hours i got a new tank and had a lot of stress over the issue.
I say remove the fish, and cut out any old silicone.
Apply new silicone along all sides of the tank.
Better safe then sorry...

wow thats my worst nightmare to have 400 pounds of water just leak, i had one once in the first tank i ever got and used silicone to fix it i forgot if it actually worked though.

Matt E. fish lover wrote:


I was just glad it wasn't the big tank, for i couldn't have replaced that one that quickly.

Are you certain its a leak? no way the fish are splashing water out the tank? if your certain its leaking then its probably best to drain the tank. cut away the old silicon and reseal it. if you placed silicon over the old stuff it will never hold. silicon can't stick to silicon once it has dried. you can place paper masking tape around the tank, say every foot or along the seams. this will give you an indication as to the height of the leak and where it is by watching what part of the masking tape gets wet. if the leaks near the top it may be an easy job to repair. best of luck with it, hope it works out better than Noddys ))

marcus wrote:


This is exactly what i was thinking.

If the tank is leaking then you need to move your fish,heater and filter to a tempoary home (a large plastic tub will do). Then completely dry the tank and reseal all the silicone holding the tank together. Years ago i had a little community tank that leaked near the top. So i drained half the water out and resealed around the leak. 1 day after refilling it, it leaked again but lower down. This is why you need to reseal all the tank. The silicone sealant (is has to be pure silicone or aqaurium sealant) isnt expensive. Check out ebay

i turned the lights off and this helped some thanks