How about these?
You know the difference between frozen foods by touch alone!
(Bloodworms have squared corners, mosquito larvae are slightly rounded, etc)
The hose from the reservoir holds 150ml water (useful when filling a 1litre jug)
You can mix water in a bucket to an almost precise TDS
level virtually every time.
You don't know why, but something is wrong, so you check, you find, you fix!
You have a dedicated freezer for a bulk buy of frozen.
Everything in the kitchen can also be used in the fish house!
Whisks, jugs, knives, chopping boards, a kettle etc. (now permanent items)
You have more tanks than you can fill, just in case!
Even if you have all that, you still want more!