HELP - My pond has drained!

I have a pond of around 5000 litres. It has a powerful 6000l pump and pressure filter.
The pond is a pvc liner with proper underlay underneath.

I cleaned the filter the other day and removed one of the connections on the filter to lower the pond height by draining it through another hose and then reattached my waterfall hose and left it alone. I installed everything originally including making the hole etc so know exactly what is what with my pond.

I HOPE it was just a leaking joint where I reattached my waterfall hose to the filter and gradually the pump pumped out the water through that leak.

I've never had any water level issues before apart from the usual evaporation during better weather and filling up with excess rainfall.

What's confused me, there's a large what seems like trapped air under my liner as I'm refilling. I sincerely hope this isn't water under there which might indicate a puncture liner? But there's no air bubbles rising into my pond when I'm pushing the huge 'bubble' around.

What I'm asking is, is it possible this is just air under there that will gradually escape as the water puts more and more weight down?

 

Update!

I've been filling the pond and switched the pump back on again (thankfully no damage due to running dry! Oase quality!) And instantly the problem was found! The ribbed pipe near the connection from the filter had split! Absolutely no reason for it, it's a relatively straight pipe. But boy did it shoot out! At that pace it would have drained my pond in about an hour!

The bubble has sunk quite a lot now, possibly even completely flattened out. But there's a lot of water travelling down the paths now so if it was water, the pressure in the pond now is squeezing it out and away. 5000l had to go somewhere!

Just gotta keep an eye on it now and my fish which thankfully found a shallow end to swim in to ensure there's no problems with chlorine etc. I've poured in a lot of treatment so fingers crossed.

 

Hallo Brind,
your post filled me with dark memories of waking up to gaze romantically at the pond at the bottom of the garden, envisaging the usual cluster of "the greedy ones" by the edge awaiting their breakfast.
WHAT!! That shock of seeing black liner exposed for the first time for years never completely goes away so I understand your anguish. It will take quite a while for the wet to dry up but I hope for a dry weekend for you and the new connection does the trick. So glad you had a bolt hole too,
Jenny namaste

 

Having come back from teaching on Saturday to hear the sound of a pump pushing air, rather than water, I know that panic feeling well. I lost one shubumkin, but the other two survived, though I have no idea how. They are now recouperating in the garage, whilst I work on how to persuade hubby to allow me to install a pond at least 2 years ahead of plan!

 

Thank you for the up date hope all is well Today