Keith in my experience, most every chemical mixes better in a good pH environment. Low Ph's don't usually mix well together. So if the two additives, when mixed together, it gets thick?? So it sounds to me this might be caused by introducing the lime to fast or the Ph gets to high and it causes it to get thick. In my business I would add a thinner, but I would not do this to my pond, but I might add sodium bicarb to the mix and see what might happen? I don't think it would hurt the fish, and might even help with indigestion.
Tracy
PS, my sediment pond is dirty right now, I might have to do a little mixing of the alum and lime together and see what I might be able to do with it
