Ok guys...need some input. I know aquatic plants and I know human medicine.....but I am thinking my Pleco is sick...His poop always looked like dark grey rubber washers in long strands...you know, normal. As of late, his poop is pure white. I am seeing white poop on some of my other fish too. I think it may be a parasite because the color is not normal. Is it? If so how do I treat it...and also where do you suppose it came from??? Please help~