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.
Here is the basic Â«recipeÂ» to use if you canât boil your liquid directly. 1  1. Dissolve 1 tbsp agar flakes or 1 tsp agar powder in 4 tbsp hot water. 2  2. Bring water to a boil. 3  3. Simmer for 1 to 5 minutes for powder and 10 to 15 minutes for flakes.  4. Mix well with warmed ingredients.