When putting cover in a BOW, think of the fish size that you want to benefit from said cover. Smaller fish need smaller spaces between the branches, larger fish need larger spaces.
i.e. if you want to make protective cover for newly hatched fish and YOY, make the cover dense. If you want to have cover for ambush points for predators, have much larger spaces between the branches.
Using cedar trees for an example, 1, maybe 2 year old (in the water) cedar is good for YOY fish. As the branches decay and degrade, the cover will be good for larger and larger fish, if they prefer to relate to vertical cover. Some fish like horizontal cover, like a log to get under to get out of the direct sun in shallower water.
To help save on labor, I prefer to use non-biodegradable cover for small fish. Put it in the pond once and it's good for a long, long time.
