Additives in gypsum slurries and adjusting their proportions

A gypsum slurry comprising:

• calcium sulfate hemihydrate;
• water;
• a dispersant component selected from the group consisting of a comb-branched polymer having polyether side chains, naphthalene sulfonate-formaldehyde condensate, melamine sulfonate-formaldehyde condensate and mixtures of two or more thereof;
• a foaming agent;
• and
• a polycondensation component comprising:
• a first polycondensation repeating unit having a polyether side chain and one of the group consisting of an aromatic sub-unit and a heteroaromatic sub-unit;
• a second polycondensation repeating unit having a OP (OH)2 group and one of the group consisting of an aromatic sub-unit and a heteroaromatic sub-unit;
• and
• a third polycondensation repeating unit having one of the group consisting of an aromatic sub-unit and a heteroaromatic sub-unit;
• wherein said second polycondensation repeating unit and said third polycondensation repeating unit differ exclusively in that the OP(OH)2 groups of said second polycondensation repeating unit are replaced by H in said third polycondensation repeating unit, and said third polycondensation repeating unit is not the same as said first polycondensation repeating unit;
• and
• wherein the weight ratio of the dispersant component to the polycondensation component ranges from 1:99 to 75:25.