1 A do-it-yourself approach for basic basement steps starts around $250-$350 for materials, and takes about 3-4 hours. 2  That's with standard lumber, such as pine; costs can go much higher with more expensive wood, such as oak.
Pour enough melted agar into each sterile plastic petri dish to cover the bottom - about 1/8 to 1/4 deep. Replace the lid immediately. Place agar plates on a counter top to cool and set. Agar medium will set like stiff gelatin at room temperature. The agar medium is now ready for storage or use.
1 Soak grates and caps in a slightly diluted solution of liquid cleanser and scour with a non-metallic soap filled pad. 2  Place the grates and caps in a sealed bag or covered container with 1/4 cup of ammonia. 3  Let sit 3 hrs up to overnight to loosen soil. 4  Rinse thoroughly and dry with a soft, clean cloth.