Bonsai Soil - Ibaraki Hard Akadama(6mm~10mm) 13L 9.5 Kgs (Medium) https://www.amazon.com/dp/B06ZYP2HFS/ref=cm_sw_r_cp_api_i_YlJbBbDRWEW8S
I made a sieve with hardware cloth, but all I could find was quarter inch so there was a lot of hand sifting going on too to avoid that muck