Leaking Tank?

Spotted some water outside the bottom of the tank today so wiped it away.  It was between the glass and the plastic surround/base the tank sits on.  A bit later on and it's back so I wiped it away again.

Now I've stuffed a cloth in the gap and it's beginning to soak quite a bit up but there seems to be no letup in the water collecting there away from the cloth.  (See pic) 

So I went out and bought an 80L storage container that I can hopefully set up as a temporary home while I empty the tank and apply some aquaruim sealant to the inside seams.  I tested the container with 40L water (much to SWMBOs disgust) and it held well with no significant bulging.  That's why I got a decent size one to hopefully avoid stressing the sides.

The water level hasn't dropped in 3 hours of measuring so it's not a major leak.  I'm just worried what it might become if left unfixed.

Before I start, has anyone had this problem themselves and/or can advise please?

Thanks Sue, I'll try that. 

I must admit, it does tend to dribble when I remove the hood for water changes etc, but I normally try to catch it as it runs down the glass - front and sides at least but I can't easily reach the back.

I've got a condensation tray I can fit to stop any potential jumpers and I'll lower the water level slightly too.

Well I took your advice and fitted the condensation tray and opened the hatch overnight.  So far no increase in water escape so it may well have been that. 

I did have a couple of spacers to a) hold the condensation tray which is slightly undersize, and b)  lift the lid a couple of mm off the sides.  But as my lid has an internal lip to allow condensation to drip back inside that may have been a bad idea as water may have been collecting on them and diverting down the outside.  They're now removed.

Many thanks Sue, panic over - but I'll keep an eye on things over time.