Yes, lots of "dirt" came up, but I felt that was bad thats why I deep cleaned the entire tank.
Although my water quality is good (ph 6.4, tds 100/120, kh 1 or 2, gh 5, nitrate/nitrite 0, ammonia 0, temp 85), I feel that with the size of the fish and all the feeding that discus need, my substrate must be loaded with waste.
95 Gallon Discus/Planted Tank
30 Gallon Planted Tank
50 Gallon Reef