And I thought that it starts by submerging the siphon and shaking it up and down to start sucking, which is very difficult, but the correct way is to submerge it horizontally, take it out of the water and dive it again (there is a video on the internet with different brands) and it starts very easily like that. Although it sucks very well by doing this, it has 2 significant problems. The rubber is very hard and not convenient at all, and also if you lose suction while half of the water has been emptied, you cannot restart it due to the altitude difference.

We bought this because it is a brand and seemed a little better than the completely cheap but fake ones. The type of pump it has is a patent from Lidl and you shake it up and down and it pumps. But it is completely unusable and can even damage the aquarium. Also, after 7 uses, it broke. The black boards that hold the hose in the part of the vacuum cleaner and allow it to rotate had started to bend and let in air, and in the end, it broke completely. It lasted 7 times, completely wasted money. Get the completely cheap one, it is by far a better design. Just a hose with a hand pump and that's it. Reliable, doesn't break, and costs half the price