I did a large water change today and I was syphoning near a cluster of plants. Suddenly a huge red/brown cloud exploded out of the gravel! I was like Ahhhhhh whats happenening!!?!? And then I realized it was one of th root tabs I thought it would be like a slow-dissolving tablet so you could still syphon without worry....I guess not! I think I've got to be more careful when cleaning my tank now.

yeah, its a shock first time that happens!!