As noted above, most kitchenware can be well rinsed to insure it is soap free. However, very early on in my fish keeping adventure I bought myself a dedicated set of the Pyrex measuring cups- 8, 16 and 32 ounces. They are only used for fish stuff and these would work fine for your needs as well as a whole host of other fish related tasks. I also feed a lot of frozen food and I use a couple of the hang-on specimen boxes on occasion for this. I tend to either pour food directly into a tank or else into a small strain and then dispense it from there either dumping it all in or useing a large 10 inch tweezer to put in smaller portions.