Why do aquatic plant pots have no holes or are full of holes/mesh?
Pots with no holes in them are intended for containing clay soil that can be added during planting. When placing the plant in the pond or when moving them into new arrangements, the soil will stay contained in the pot. If you are using a pot containing clay soil, be sure to add some large rocks on the top of the pot to prevent the soil from spilling out. Active fish and other aquatic life can push the soil out of the pot if they move to close to the top of the pot. If the rock you chose to cover the pot is still being knocked out (as is often the case with pea gravel), replace the rock with larger rocks. Mesh pots and pots with holes are usually intended to contain a planting media other then clay soil to secure the plant roots.
