Well my first post is a little tool/invention I am particularly happy with. I have a 10g Betta tank with sand substrate.
To clean the Betta droppings, I have tried a gravel vac, (way to strong and fast) a baster or 3 all of which worked but a while and would splash water out when I tried to move the baster over a dirty water receptacle. Also tried a syringe with tubing, but the capacity was only a little better than a baster.
My plan to create a quick easy tool for cleaning the top of the sand led me to combine a Stream Machine water cannon, superglue, and a baster's nozzle end.
The result is a highly adjustable vacuum that holds the water until dumped, and holds a good deal of water.
I have attached a couple pics, and really like this item. Perhaps I should patent or market???