I averted an overflow problem this morning, luckily at home
One of my Super Tongan Nassarius snails decide to go on a walk about, and these snails are quite happy to go out of water, over the overflow gate he climbed and into my durso. He stopped the flow enough for the auto-top up to kick in and keep fulling up the tank. When I noticed the tank was 25L fuller than it should have been and about 10mm away from overflowing.
I have quickly installed a plastic grid over the durso so these boys can't get in here again.
So keep this in mind if any creatures are able to get into your overflow box
One of my Super Tongan Nassarius snails decide to go on a walk about, and these snails are quite happy to go out of water, over the overflow gate he climbed and into my durso. He stopped the flow enough for the auto-top up to kick in and keep fulling up the tank. When I noticed the tank was 25L fuller than it should have been and about 10mm away from overflowing.
I have quickly installed a plastic grid over the durso so these boys can't get in here again.
So keep this in mind if any creatures are able to get into your overflow box