None. Fresh only. Organic or at least pesticide-free.Going to feed fresh organic spinach,zucchini and carrots but was wondering about canned vegetables
Fresh carrot should typically be avoided, as it's loaded with sugar which can quickly foul your tank's water. Only a few varieties are really suitable. They really need to be processed (from fresh) into something else if they're going to be fed and you aren't sure of the variety.
Green bean isn't a great option. Fine to feed but not a lot going on for it.
Kale, spinach, zucchini, nettle, that sort of thing - with zucchini being the lesser option. Spinach is great for shrimp because its cell walls break down easily and it's calcium-rich. As @Mbrman suggests, it's also one of the easiest fresh foods to store. Just roll up a baby spinach leaf into a little ball and chuck it into the tank. Or, if you're me, you roll up several dozen and keep them in the freezer. No need to thaw or anything. Freezing breaks down the cell walls quite a bit and makes spinach a big hit with shrimp.