Black Concrete Powder is used to make black concrete blocks. You can place this powder in the water to make black concrete blocks.
To make Black Concrete Powder, you will need Sand, Gravel Blocks and Squid for Ink Sac. Please follow the following steps to make Black Concrete Powder.
The next required item that you will need to get is gravel block. Get at least four of them using your iron shovel.
Squid for Ink Sac
After that you will have to find and kill squid to get ink sac. You will find them under the water. Use your iron sword to kill a squid.
Black Concrete Powder
Now you can finally craft Black concrete powder as you have ink sac, sand blocks and gravel blocks in inventory. Add these things into 3*3 crafting grid of the crafting table in the same way as shown in the following image. Add 4 gravel blocks at the four corner cells, ink sac in the center cell and 4 sand blocks in the remaining 4 cells. You will get Black concrete powder in the right-side box ofthe crafting table. Add this item in your “ready to use” stock.