A process for flocculating filler particles in water is provided. The process comprises adding a flocculant to a mixture comprising filler particles and water, wherein the flocculant has a reduced specific viscosity (“RSV”) of from about 5 dL/g to about 16 dL/g, a viscosity average molecular weight of from about 1,200,000 to about 7,500,000, and a cationic charge of from about 5 mol % to about 50 mol %. Flocs formed by flocculation of the filler particles and the flocculant have a median particle size of from about 10 μm to about 150 μm. The filler is not precipitated calcium carbonate alone. The flocs provided by the process are useful in increasing ash content of a paper product.