We describe a simple procedure for optimising the growth condition for high-quality single crystals of the strontium ruthenate perovskites using an image furnace. The procedure involves carefully measuring the mass lost during crystal growth in order to predict the optimal initial atomic ratio. Using this approach we have succeeded in growing crystals of Sr3Ru2O7 with a residual resistivity as low as 0.25 muOmega cm. The procedure we describe here is expected to be useful for other systems when a standard travelling-solvent floating-zone method cannot be used because of high volatility of a constituent material. (C) 2004 Elsevier B.V. All rights reserved.