The discussion revolves around the idea of filling a fish tank with M&Ms instead of water. The tank dimensions are approximately 30x12x18 inches, leading to calculations about how many bags of M&Ms would be needed. Initial estimates suggest around 3-4 large bags might suffice to line the bottom, while some participants humorously exaggerate the number to thousands of bags. Suggestions include using various candies to create a whimsical candy aquarium, with ideas like gummy fish and candy rocks. The conversation shifts to playful banter about cooking, personal anecdotes, and the impracticality of using M&Ms in a fish tank due to potential staleness and attracting pests. Ultimately, the thread highlights a mix of humor, creativity, and friendly debate over the feasibility of such a candy-filled aquarium.