Yeah, Doom mentioned that when I was talking about putting a sweet pepper in the tank - apparently it can 'burn' albino fish. BTW, my Albino BN never showed any 'burn' after his lunch on a piece of yellow pepper, but still, I will never put a piece in my tank with the skin on again. Great tip.
BTW, blanching to make the vegetable sink is, I suppose, one reason to blanch, but you can just take that piece of raw zucchini/spinach/pepper and secure around a rock with an elastic.
And hey, littletank, you are almost right about cooking vegetables! But blanching doesn't mean boiling for five minutes, it just means immersing for thirty seconds in boiling water and rinsing immediately in ice cold water to keep the colour and nutrients intact. At least in my culinary world, that's what 'blanching' means - I'd think that might be the same for feeding fish?
I've even accidentally put raw spinach in my tank - the tank water softens the leaf pretty quickly, and my fish devoured it.
But I think it would be important to wash the veggies well, if not blanching them, to get rid of any pesticides.