World renowned fine mesh pots were invented by Anglo Aquatic and trademarked Finofl.They have a coarse mesh structure in-filled with fine mesh. The coarse mesh gives superior strength and the fine mesh reduces soil loss compared to other baskets on the market. Although others have copied, Finofl are still the highest quality aquatic pot available hence they are used by growers around the entire world. Their invention eliminates the need for hessian while still allowing water to circulate through the soil bringing essential oxygen and nutrients to the plant.
If algae is already present, increasing the number of oxygenators will help to slow/stop it multiplying. Snails and mussels will help to reduce the amount but there is no better solution than netting it out manually to give these natural solutions a helping hand.