These free swimming ciliates work on eating free swimming single celled bacteria and help to lessen the TSS in the water.  They are found during any sludge age but are dominant during high F/M or young sludge.

This photo of branched stalked ciliates is taken at 200x Bright Field

Stalked ciliates are found during most sludge ages but usually are dominant during middle aged sludge. They are typically indicators of good healthy, quality sludge age.

This picture is phase contrast at 400x

The picture of the suctoria is shown capturing a flagellate on the left side.

To the right of the suctoria is a zoogleal floc structure.

Suctorians are excellent indicators of good sludge.

The picture on the right is a rotifer. This picture was taken with Bright Field at 200x

Rotifers are multiple celled organisms that feed on good, stabilized floc. They are highly sensitive to high BOD loadings and toxic shocks. They are typically found in conditions with low F/.M ratios, high MCRT or high MLSS rates.

The picture on the left is 100x Phase Contrast

This is a nematode

Worms are free living macroinvertebrates. They usually indicate very old sludge, high MLSS, low F/M ratios or high MCRT. They crop bacterial populations and recycle nutrients. Nematodes and bristle worms are the most common worms found in wastewater systems.