They break down plant and animal remains and waste into molecules that producers reuse to make energy.

DECOMPOSERS

Explanation:

Decomposers (Figure below) get nutrients and energy by breaking down dead organisms and animal wastes. Through this process, decomposers release nutrients, such as carbon and nitrogen, back into the environment. These nutrients are recycled back into the ecosystem so that the producers can use them

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added