In article , Ron Clark
writes

Yes, it's low-grade spam and contains recommendations
for commercial products, with reference to stockists, ordering
information and price lists.

It's spam. It does advertise and recommend at least 2 commercially
available products


So, it's OK to have a website showing you how to make a cheap pre-filter
for a pond, so long as you don't tell people where they can buy the bits
to do it?
I can only assume:
a) Troll
b) seriously sad life

You need a holiday ( a very long one!)
--
Jeff Taylor