Well I use fresh pea's but yea frozen 1's thawed out and squish them a lil with a fork or so that the outer shell cracks some - My Cory's always been going CRAZY over that.
Squash they like as well BUT that's where my fish & I battle who gets it LOL nothing comes between me & my squash
Technically the cube would thaw out in the tank water yes....but any & all fish I ever had are RIGHT THERE when it comes to food and I just find frozen foods very unnatural so I just have lik 1/4 cup measuring cups I dip in each tank to get a lil tank water pop that cube in tehre and let it thaw out a few mins and then add it for the monsters.