- Hi, this is Wayland, from Marine Depot.
Today we're taking a look at ion-exchange resins.
We'll discuss if they're helpful
for keeping your water clean in a saltwater aquarium.
(upbeat music)
There has always been confusion, and a bit of skepticism,
about using ion-exchange resins in saltwater aquariums.
The truth is most resins don't work at all in saltwater,
but there are some specialty resins
that can greatly improve water quality in a reef tank.
We'll explain why this is,
and how to select resin-based filter media
that will really work in your aquarium.
The first resin-based aquarium filtration product
was introduced to the hobby in the 1960s.
It's important to understand what ion-exchange resins are,
how they work, and why you would consider using them
in your saltwater aquarium.
Typical resin beads are about 1 millimeter in size,
and are made from either acrylic or polystyrene.
When manufactured, the resin goes through
one or more chemical treatments
to create custom ion exchange sites
located throughout the bead.
Resins with different properties are created
by altering the chemical treatments
used to manufacture the resin beads.
For example, some resins are made for water softeners,
the removal of calcium and magnesium from the water.
You'll find these in residential homes and hotels.
A different process creates resins
that remove nitrate from drinking water.
You may be thinking any nitrate removing resin
will be great for a reef tank.
It sounds like a great idea, but it won't actually work,
and here's why.
Ion-exchange resins work by trading one ion for another.
Let's look at a water softening resin.
The resin has a negative charge that attracts positive ions.
Positive ions are also known as cations.
It's called a cation-exchange resin
because positive ions in the resin
are exchanged with other cations in the water.
The manufacturer loads softening resin with sodium ions.
As freshwater flows through a bed of resin,
the sodium ions are exchanged for calcium and magnesium.
Water hardness is removed, and the sodium's released.
Once the exchange capacity
of the softening resin's exhausted,
it's flushed with saltwater,
which is why you add salt to a water softener.
This strips off the hardness minerals
and reloads the resin with sodium ions.
But what happens if this resin was used in a reef aquarium?
Would it actually remove calcium and magnesium?
No, it won't remove anything,
because aquarium saltwater's too high in sodium ions.
The exchange process won't work
due to the high sodium content of the saltwater.
A similar principle occurs with nitrate removing resin.
Anion resin has a positive charge
and attracts negatively charged ions, also known as anions.
The resin is loaded with chloride ions by the manufacturer.
As freshwater passes through the bed of resin,
the resin trades chloride ions for nitrate ions.
The resin is recharged with salt to remove the nitrate
and replenish the resin with chloride.
But the resin cannot exchange ions in saltwater
because the chloride level's too high.
The exchange can't occur.
Unfortunately, many of these typical resins
have been offered to the marine hobby,
along with inaccurate claims of ammonia, nitrite
and nitrate removal.
As we've just seen, standard resins just won't work
in saltwater.
Fortunately there are specialty resins
that do actually function well in saltwater.
They're called organic scavenger resins.
They're made specifically for saltwater aquariums.
These unique resins have a porous structure
designed to capture dissolved organic compounds.
The manufacturing process
creates a highly specific porous internal network,
with specific absorption characteristics
that don't rely on ion exchange process.
Resin manufacturers fine-tuned
the absorption properties of resins
for specific applications, like decoloring sugar
and tannin removal from drinking water.
There are many scavenger resins,
but not all are effective in saltwater aquariums.
The best scavenger resins capture both medium
and long-chain organics
responsible for the discoloration of water.
You can actually see the resin turn brown
as the organics are trapped inside the beads.
Fresh scavenger resins are white, clear or amber in color.
They'll turn tan or brown as organics are captured
and concentrated inside the resin beads.
You may be wondering what the difference is
between activated carbon and organic scavenger resins.
Resin-based filter media are more expensive,
but you're getting a more efficient filter media
designed to remove organics,
like those that build up in our aquariums.
Unpublished research by an aquarium product manufacturer
found that certain scavenger resins,
when combined with coal-based activated carbon,
worked better than resin alone or carbon alone.
The same resin blend was found to be highly effective
for removing organics from the groundwater
by water treatment facilities.
You can also use a resin-based media without carbon.
Just pout it into a filter bag
and drop it into your sump or your filter.
Also, some resins are able to be regenerated at home.
There are a variety of carbon resin products to choose from.
The performance of each brand
will depend on the type and amount of resin
blended with activated carbon.
The label should state
that it contains specialty scavenger resins
that remove organics.
If you're having an issue with phosphate, nitrate,
or algae growth, a resin-based media can help.
The organics removed from the water
won't have a chance to break down
and form algae-producing nutrients.
The best advice is to experiment with different brands.
Look for a clearer water and better light penetration.
If you have any questions,
feel free to message us
on social media,
or give our excellent customer service team a call.
Don't forget to like, subscribe and comment below.
Thank you for watching our video today,
and, as always, let's build a better aquarium together.