The production of low-cost open-pore ceramic materials from fly ash (FA) and marble waste (MW) was investigated. The effect of MW (5-40 wt.%) on the open porosity was determined. To reduce the sintering temperature and improve the properties of porous materials, the mix-tures were activated with an alkali solution. Samples pressed from FA and FA+MW mixtures were sintered at low temperature (900 °C), but sufficient strength could not be obtained. How-ever, when these mixtures were subjected to alkali activation, pressed and sintered at 900 °C, sufficient strength and porosity values were reached. The open porosity of the MW neat spec-imen was 12.70%, but it increased up to 39.91% at 40 wt.% MW, which was the highest ratio used in the literature. The main phase structure was nepheline at 0-20 wt.% MW, but gehlenite became the dominant phase at 40 wt. % MW. The compressive and flexural strength values of 40 wt.% MW added specimen was determined to be 12 and 5.35 MPa, respectively. The open-pore ceramic of high MW ratio, produced by this new alternative route, has the potential for use in water purification membranes for macro filtration purposes.