This edition of Filtration Nation asks three questions of
pool and spa filtration expert
Richard Medina.
AQUA Editor Scott Webb: Over the
last 23 years, I’ve written dozens of
pool filter stories, but I’ve never talked
about antimicrobial media. All this time
I’ve wondered — why is antimicrobial
media even a thing? I mean, your
water’s got chlorine in it — isn’t that
already killing the microbes before they
reach the filter?
Rich Medina: Yes, chlorine is sanitizing
the pool, but as we know, there are
times when there’s less free chlorine
in the water than others, maybe not
enough to kill all the algae or bacteria.
At the same time, invariably, you
wind up trapping on the filter media
some of the stuff that the algae feed
on, and potentially that is a growth
vector for algae that has survived
[poorly] chlorinated water. At that point,
you do have the potential for growing
something on the filter media that is
somewhat resistant to chlorine.
So from that perspective,
antimicrobial media provides some
peace of mind to the user — it helps
prevent you from harboring bacteria
and algae on the filter.
Just to be clear, anti-microbial media
is not going to actively go after the
bacteria that is in the water, or leach
anything into the water. It’s something
that prevents the growth of mildew or
bacteria on the surface of the filter.
SW: Okay, say it did start growing
there, would it kind of block the filter?
RM: Yes, you would see a reduction
of the effective flow. Algae is a
pernicious organism that would
basically blind off the cartridge media
to an extent. I should add that not all
antimicrobial media are identical. Some
are dip-coated, and some have the
antimicrobial agent built right into the
fiber — it doesn’t wash off or anything
like that. It’s in the fiber itself.
SW: Here’s another question I’ve never
asked but always wondered about. The
basic technology of pool filtration is still
more or less the same as we’ve had for
ages. Do you think that’ll ever change?
Will we ever get some kind of a really
new way of achieving pool filtration?
RM: Yes, I really think so. There’s a lot
of technology that’s brewing out there.
Also, I personally believe our overall
energy paradigm could change — that
we could solve some of the energy
challenges we’re facing right now. If that
happened, that would change how we
approach filtration.
Sooner or later, I think we’ll find a
solution to our broad energy problems.
For instance, if battery technology
continues to advance, the ability to store
large amounts of energy — whether it’s
from solar, wind or some other source —
would definitely allow us to capture more
than we need.
If that happened, clever people in
the pool and spa industry would figure
out a way to harness this abundance of
energy and come up with a new kind
of filtration system. If you think about
it, all you’re doing is moving molecules
around to take debris out of water. There
are a lot of ways you could do that if you
had enough energy at your disposal.
Richard Medina is an engineer whose decades-long
career in pool filtration spans all three
major types of filter media — D.E., sand and
cartridge. He was senior vice president of
engineering at Pleatco for 13 years, and vice
president / general manager at Columbia Pool
Filter 15 years before that. He currently works as
a filtration consultant for OnCore Filtration in
Manning, S.C.