Try an auto store... I found a siphon pump in there. I have no idea what it's meant to do regarding cars, but it sure works for pumping water into the tank from a bucket. It's really, really slow (compared to tipping the bucket) so if I have to lift the bucket a long way (I had to put some tanks up really high to save space) I half fill the buckets. Fiddly, but nothing on operating a hand held squeeze and release pump for half an hour. I only use the aforementioned pump doing water changes on my betta tanks, which are converted 2 gallon jars, and because of the round tops are very easy to slip the bucket off and drench myself and anything nearby. Which happens to include my electric piano, computer, 2 powerpoints, and generally a few hours worth of homework. (The latter, I wouldn't mind having a good excuse... 'my fish ate it?!')
But yeah... this doover is basically a red plastic bulb with two lengths of tubing coming off it. There are valves in each one. You squeeze the bulb, the air goes out, you let it go and because one of the valves sucks closed, it sucks in water. Then you keep squeezing it and letting it go. By using it in reverse both valves stay open and you can use it like a regular length of tubing to siphon water out of the tank to a bucket below. And I got it from an auto store. Go figure.