Growing of phytoplankton under controlled conditions - using hypodermic needle to draw air from thick-walled hose for delivery to plastics bag contg. sea-water

摘要

Small plastic bags filled with sea water are used to grow phytoplankton under controlled conditions. The water is supplied with purified air which is free from any contamination. The air is taken from a thick walled rubber hose by means of a hypodermic needle connected to a small bore pipe. The hypodermic needle is plunged into the wall of the hose and the elasticity of the rubber causes it to press against the surface of the needle so that no air escapes. On withdrawing the needle the hole closes up.