Water pump question

[maxshafer]

Hi, thanks for the great resource. I am trying to build a version for feeding other fish species (cichlids), and our food is slightly bigger than the standard zebrafish GEMMA food (0.5-0.8mm for cichlid food).

We've had some issues finding the right kind of water pump for transferring the food to our tanks. We've bought some that just end up with food stuck in them. I have been trying to figure out what it is about the design of the suggested pump that allows the food to go through.

For example, this one seems to be of the same design (and available here in Canada), but I am unclear if that is the case.
https://www.amazon.ca/gp/product/B0711RC7DB/ref=ox_sc_act_title_1?smid=AMFH8PFQ4G2A0&th=1

Ideally I would find one that could accommodate different sizes of food.

Thanks for any help!