So I just completed my weekly water change and discovered a minute trickle from the front left corner of the tank! It only just started after this water change, of that I'm 100% sure. I dabbed at it gently with a towel, and it seemed to stop. It lasted all of about 30 seconds, but it was definitely happening!
It also seems that from the front of the tank there are some minute specs of water underneath the seal.

So, advice please guys?
I'm worried the tank will burst, and in a rented apartment, that won't go down very well with the landlord...

First be certain it's a leak and not spillage from the water change or some sort of capillary leakage due to the fill level or air stones etc. What tank is it - is it a known make or a plain glass tank?

Dry the area where it appeared to leak very thoroughly. When you're sure it's dry, push some kitchen roll or similar into the area and check later for dampness. Also mark the water level on the glass to see if it drops; though with a very small leak you may not see a significant drop in the level. Dry and clean the glas well too, and check later for runs or drips on the glass coming from the top of the tank via capillary action.

If it does turn out to be leaking you will need to act, as once water has penetraed the seal and found a path out the gap will enlarge with potentially disastrous consquences.

It's a Tetra Aqua Art 60L glass tank, approx 3 years old.
I don't think it was spillage as the seal evidently had water underneath - although there was only a minute amount. Also, when I dried it thinking it was a spillage, it trickled visibly. The water that was trapped under the seal has slowly disappeared, but not leaked out of the tank.

I dried the area thoroughly, and it stopped. That was over an hour ago, and there's been no more leakage. My concern now is that the seal has been compromised to an extent, and I'm wondering where the bits of water that were under the seal have disappeared to.

That tank has a plastic tim at the base that the tank solts into doesn't it? I suspect the seal itself isn't compromised as that trim is not the seal, there will be a silicone bond inside there between the bottom and sides of the tank.

The trim is for aesthetics and to provide a support for the base. It's easily possible that some water ran down into the trim during the water change and it would appear to trickle as you tried to mop it up (have seen this with similar designs) rather than the actual underlying seal being compromised. The small amount remainig will have evaporated over the last hour.

Place some kitchen roll against the suspect area and if there's no more dampness I think my explanation is probably the right one.

The 'leak' was coming from the left hand vertical seal, about half way up the corner of the tank.

But I'm not sure now, I think I might have just got myself panicked! I've inspected the corner really well, and I think what I thought was the seal lifting is just the way the 2 panes of glass are sealed together. And the bubbles of water underneath were between the panes of glass itself, not worked their way under the seal.

Anyway, vigorous monitoring will be done over the next 24-48 hours, and for my next water change I will look to see if I can recreate the 'leak'. Possibility it was just coming down from the hood after I closed it!

It's funny how tunnel vision can stop you from seeing logic!
Thanks for your advice Fishlady!

I sincerely hope it's not a leak - I know that panicky feeling when a leak is suspected all too well. The last time it happened to me it was real - I dropped a piece of rock on the floor and didn't know it had hit the back of the tank on its way downn. There was a huge crack in the glass which I found when the tank was half-empty

Good luck with yours, hopefully just an optical illusion and a little spillage

Well, fingers crossed!
Oh dear, that sounds like a bad day!

I've already told the OH that it might be leaking, and may be an excuse to get myself a bigger tank... Hehe!