I have one of those cheap ($10) Aqueon siphon vacs with the black pump.
Works ok, but barely has the power to pick up poop.
Today, I changed out about half of the water I was planning to change, and when I emptied the bucket and started up again, I could not get it to pump the water anymore than halfway up the tube. There's got to be a leak or a hole somewhere, but I can't figure out where.
What are my options to replace it? I thought about a python, but I don't want to use the python to refill, because my water needs to age, the pH goes up almost a point after a day, and I don't want to cause ph shock to my fish.
The Eheim Quick Vac Pro looks like it works well as a vacuum, doesn't actually drain the water, so I'd have to use another method to do that.