This is what my (call us paranoid, but I like the idea anyway. I'd like to share this, and wonder what do others think?) partner has done to improve the external filter system we have. Since there is an output hose and an input hose, we punched a hole at the top (~1cm) just below the water surface. So if one or both hoses get dislodged by accident, or even if the filter pump starts to go haywire, we will not lose more water than the 1cm volume I have not seen this "security" feature in other pumps so far, but it's not that difficult to drill a hole in the plastic input/output hose I have. Thought we'd share this here

you punched a hole in the intake tube? Won't it only suck from the top hole then? If so, why not put the intake tube bottom and stick it near the top of the tank?

sounds good.. but.. does water escape from that hole?? and does it cause your water to be weaken??

Just a very small hole, so it won't really absorb only from the top. The reason why I kept my normal intake suction area (?) at the bottom of the tank is to be able to suck dirt closer to the ground - sounds like a standard thing from other filters around. Plus, it will look weird to me to have a short intake tube.

sounds interesting! Didn't know that would work, have you tested it? If the hole is small, won't it still come out but just slower?

One pipe is an input pipe, the other output, but when either act as a siphon during an "accident", the hole will cause air to be sucked in just at the 1cm mark. I've tested this, and seems that even with a very small hole, a small amount of air causes the siphoning action to weaken, weaken, and then stop completely. Good enough for me, I prefer to lose only a small volume of water than everything. I hope this is a completely fool proof way, and will appreciate if anyone can point out any failure point to this setup