inlet strainer attaches to the inlet extension and prevents gravel and
other debris from clogging the filter. It is recommended to mount the
strainer no closer than 4 inches from bottom of the aquarium to avoid
disturbing the gravel in the bottom of the aquarium. Replace if broken
or warped. Do not operate the filter without this strainer as it can
allow larger particles to get into the filter increasing your
maintenance of the filter.