From the web page
AQUAPLANCTON brings about mineralisation. When the micro-organisms, which normally digest organic matter become inactive, mud accumulates, causing algae and blanketweed to thrive on the over nutrition. AQUAPLANCTON reactivates these beneficial bacteria which then multiply and consume the mud. This starves algae and blanketweed of nutrition, causing them to die out naturally. Good bacteria, working well, can consume up to 15cm (6") of mud in 6 months.


Don't know what 'mineralisation' is... anyone?
I think oxygen and warmer temps usually wakes up
dormant micro organisms.

If you have a typical small garden lined pond you can simply drain it
and shovel up the sludge yourself. Keeping
plants trimmed and dead plant matter and leaves from heading to the
bottom helps too.
One reason why bottom drains and skimmers are so handy
is they take the work out of that particular chore.

k :-)