I haven't wet brined in some time.
I try to use the minimum amount of liquid to keep the meat covered. Use whatever amount fits in the bag with the brisket.
The less water you use, means the seasoning needs to be reduced as well.
SmokinEdge
also gave you the rest of the story with using RC.
Getting the nitrite to 150 ppm also brings in 1.5% salt. I don't know how much salt is in your pickle, but if it was based on using cure #1 (which is basically just under 0.25% salt) you will have some very very salty corned beef.
I try to use the minimum amount of liquid to keep the meat covered. Use whatever amount fits in the bag with the brisket.
The less water you use, means the seasoning needs to be reduced as well.

Getting the nitrite to 150 ppm also brings in 1.5% salt. I don't know how much salt is in your pickle, but if it was based on using cure #1 (which is basically just under 0.25% salt) you will have some very very salty corned beef.