Because I am interested in plankton I invested in a student-grade plankton net. It’s not very large, and is convenient to launch. I do not have access to a boat so I deploy it from the shore by throwing it out as far as possible and then slowly retrieving it. On some days it takes three retrieves to get enough sample for an interesting study morning. Lately though there is so much plankton in the water that it only takes one retrieve.
You can make a serviceable plankton net from an old pair of ladies stockings. This is cost effective if you don’t think that you will want to do this very often – otherwise I recommend a purpose built one, as it will be more durable and be made of a fabric designed to filter water. I use a 60nm mesh size but you may wish to choose something else.
Care of Net
After each collecting session take the time to wash off the net under a cold water tap. Start on the outside and then slowly wash down the inside toward the drain in the bottom. Carefully hang it to dry (this should happen fairly quickly in most settings). Be careful not to damage the fabric as it could be easily torn. This should keep the net in good shape for many years – and smelling sweet.