Thanks to every body! regarding the guppies y have tryed with shallow water,without water, on the tip of my finger but..nothing! guess I'll have to wait more as you say then.. it's that what scares me is that he's REALLY losing weigth,and somewere over the half of his body I've noticed like a little bulge over the back, could it be a manifestation of the calcium lack??
-ehm..sorry if the photos are a bit messed up,but you know, was my first post and still have to exactly figure out how things work..eheh