Preheat oven to 450 degrees F (230 degrees C). Combine water and lemon juice in a bowl.

Arrange the 16 smaller pieces of butter in 2 rows on a baking dish and top with garlic slices. Place salmon fillets over each row of butter and garlic.

Melt remaining sliced butter in a bowl with minced garlic, about 40 seconds. Spoon about half the melted butter-garlic mixture over salmon and top with lemon slices. Pour about half the lemon juice mixture into the baking dish.

Bake in the preheated oven for 10 minutes. Baste fillets with juices in the baking dish, then pour remaining butter and lemon juice over the fish. Continue baking until salmon is easily flaked with a fork, about 10 minutes more.