Slow cooker Corned Beef

I like to do the corned beef thing in my Crock-Pot from already brined brisket from my local grocery mostly because I just can't afford the fridge space it takes to brine the thing myself and because it is often cheaper.  I am sure true corned beef brined myself would be amazing, but whatever hear me out.  Try this.  NOTE if you want to go the really easy way then just skip all the spices down there and add the spice packet that comes with the thing, but my suggestion would be to at least add bay leaves. 

4 lb ISH corned beef brisket
4 Cups water
1 sweet onion (yellow or Vidalia)
a few stalks of celery
3 or so carrots
3/4 Tbsp allspice (if you only have the powder I suggest using less)
1/2 stick cinnamon (or 3/4 Tbsp powder)
1 Tbsp yellow or brown mustard seed (I prefer yellow)
1 Tbsp coriander seeds
3/4 Tbsp whole cloves (or less if crushed cloves)
3/4 Tbsp red pepper flakes (or less if crushed red pepper)
1 Tbsp black peppercorns (or 1/2 Tbsp black pepper)
8 cardamom pods (or about 3/4 Tbsp)
4 bay leaves
2 tsp ground ginger (I prefer to use the tubed fresh stuff on this one)
1/2 C brown sugar

Chop the veggies however you like and toss those in the bottom of the pot.  NOTE.  If you add potatoes put those in first, then the carrots, then onion and celery.  Place the meat on top of the veggies.  Mix all the spices including the brown sugar in a small bowl then sprinkle on top of the whole thing.  Then pour about 4 Cups of water in the pot more if needed until you get about an inch above the meat.  Cook on high for 7-8 hrs.  NOTE  If you want to skip the cabbage recipe I have up then you can add chopped cabbage on top for the last hour.