Think I May Have A Leak

[Ant_Soton]

Is your filter &/or bubbler near the tank lid?

Its easy for the condensation/water to build up under the lid from splashing causing it to run around the rim & down the sides...

I think that might be what is happening !!

 

[mtbdean]

I always used to get it on the smaller tanks, until I turned the bubbles down, and actually took the stone off

 

[Rickzayne]

I got this from bubbles to close to the top... Was so annoying xD

 

[Ant_Soton]

there were a couple of clips stuck into the lid of the tank (to hold in the lighting i presume). I just took them out which leaves two small holes in the lid and the condensation on the lid isn't so bad now !!

 

[sarah40011]

i have this tank and have exactly the same happening, ive got a long water mark down the middle of the left end pane. i think youre right, its something to do with the lid design

 

[karawr]

I just set up a used 90g tank and boy was I ever mad when I thought it was leaking.

I just had it bare bottom for a bit while cycling and this big giant black bubble was forming on the bottom. But then then the bubble slowly went down and down... so I think it was a mere case of splashing.

Hope this is just the case with your tank.