Claire Corlett

Fish Food, Fish Tanks, and More
How to Lower Nitrates in a Saltwater Aquarium: Proven Techniques For Success

How to Lower Nitrates in a Saltwater Aquarium: Proven Techniques For Success


– (upbeat music) – Hello folks, Robert
from Marine Depot here and thanks for tuning in. Keeping nitrates under control
has always been a concern for aquarias because it is the
end product of nitrification and is continually
produced by the bacteria inside of your tank. For many it may seem
like a constant battle to keep nitrate under control, but the good new is there
are many proven ways to minimize nitrate build up, so here’s what you need
to know to take control of nitrates in your reef tank. First, let’s talk about how nitrate affects your tank’s inhabitants. Nearly all scientific research
about the effects of nitrate in an aquarium has been conducted with fresh water fish and inverts. This research can really not
be applied to salt water fish and inverts, especially corals. What little information that is available seems to indicate that nitrate is really not all that harmful, at least when compared
to ammonia and nitrite. Studies performed with reef
building corals, perieties, and montastria demonstrated
that nitrate levels as low as 0.3 ppm stimulated
zooxanthelae growth within the coral tissue. This resulted in slower coral growth, presumably due to the algae
out-competing the coral for rebuilding carbonates. Another study using
acropora indicated that nitrate didn’t affect coral growth at all. A study on pink shrimp concluded that nitrates should be kept below 200 ppm. From this, we can conclude
that the sensitivity to nitrate is really species specific. Nitrate is not a deadly killer of corals but long-term elevated nitrates
can inhibit certain corals from growing at full potential. There is however, another
more concrete reason to keep an eye on nitrate levels. Nitrate can stimulate algae growth. Nitrate is a great water quality indicator because as nitrate rises, so
do other organic compounds that will contribute to algae growth and negatively impact
your fish and corals. The recommended nitrate
level inside of a reef tank can be really confusing. You’ll likely get a
different answer depending on who you talk to or what you read. The facts are nitrate levels
on a wild reef, in the ocean, is below 0.1 ppm. If
we make this benchmark nitrate levels should always measure zero using home aquarium test kits. Our captive reef tanks, however, are drastically different
than a wild reef. Considering that many
successful reef aquariums keep beautiful thriving corals with nitrate levels above 10 ppm. So, the general idea for reef aquariums is to keep your nitrate
levels low as possible without stressing over a specific number. Keeping nitrates at 2 ppm or
less, seems to be the norm. The most convenient way
to keep track of nitrate is with a home water test kit. The key to obtaining accurate results is to follow the instruction
exactly as written. Mail-in water test kits
are also another option for testing nitrates. It does take more time to get the results, but you’ll also get a full analysis of you aquarium water along with it. So now that we know a little bit more about nitrates in general, let’s move on to how to control them. Water changes are great
for diluting organics and rebalancing salt and trace elements but they do not work so well
for controlling nitrate. The difficult 10- 20% water change, even if performed weekly, will never be able to
significantly reduce nitrate. This is because nitrate is
constantly being produced by the bacteria in your aquarium that processes food and fish waste. The dilution factor with the water change is simply not strong enough to
make a dent in nitrate levels and there are certainly
more effective ways to remove nitrate with less effort. As with most aspects of aquarium keeping If the water you used to make salt water and top off your tank contains nitrate you’re making things worse. You can avoid this problem
with a high-quality reverse osmosis system such as the
Marine Depot Clean Water Units. Our “O” systems will remove nitrate and a long list of other contaminates you don’t want to add to your reef tank. It’s the same with stocking
levels and fish food. The more fish and food that
you add to the aquarium, the more nitrates will be produced. Feeding and stocking is fun, but too much will certainly
get you into trouble fast. This is the exact reason
that when keeping a reef tank with corals, it is a good
practice to minimize the fish and strictly adhere to
proper feeding techniques. Biological nitrate control
is an important foundation for any salt-water aquarium.
The process is simple, bacteria convert nitrates
to nitrogen gases through a process called denitrification via anaerobic bacteria. It happens naturally in
tanks containing live rock. The tiny crevices and pores
are the ideal location for denitrifying bacteria that
require low oxygen conditions. In many reef tanks this
is all that is needed to keep nitrates under control. Along side an appropriate stocking level
and maintenance routine. In situations where nitrates
are consistently elevated alternative methods of nitrate
control can be employed. Liquid nitrate removers
in their many formulations take advantage of beneficial
bacteria in a special way. They provide carbon
that fuels the growth of denitrifying bacteria and when
anaerobic bacteria is growing at accelerated rates, even
more nitrate will be converted and removed from your aquarium water. Liquid carbon can also force other types of nitrogen using bacteria to proliferate. These nitrate fixing
bacteria can then be removed via protein skimmers. Protein
skimming will strip out the nitrogen rich bacteria from the water ultimately reducing nitrates.
This process of dosing liquid carbon into your
aquarium is often referred to as carbon dosing. Red Sea Nopox, Brightwell Aquatics Reef Biofuel, and even Vodka, are all
examples of carbon dosing. Think of a refugium as a mini aquarium tucked under your main
tank. It can simply hold more live rock for
biological denitrification, but will typically also house macro algae with the appropriate
lighting to support it. Macro algae uses nitrogen for growth and therefore when grown in a refugium, nitrate will be removed from the water as the algae grows. When algae is harvested from the refugium the nitrate comes with it. This same principal
applies to algae reactors such as the PaxBellum units. Macro algae grows inside of the reactor, consuming the nitrates as it grows. Algae scrubbers operate
on a similar concept but rely on a different type of algae. Water flows through
colonies of micro algae that are corralled inside
a scrubber chamber. The micro algae remove nitrate incorporating it into their cells. It’s important to then
periodically harvest the algae to physically remove the
nitrogen from the aquarium. Nitrate removal medias
come in different forms. Classically these medias
rely on biological activity to consume nitrates, but recently, Blue Life has presented us
with a regeneratable resin that specifically targets
nitrates and nitrates only. Biological nitrate removers
are made from porous, ceramic like materials. The porous structure’s rough surface provides an environment suitable
for denitrifying bacteria. You can think of this
media as tiny live rock. It is typically placed
inside of a media bag or inside of a reactor. Keep in mind it can take
weeks or even months for the bacteria to colonize the media and start reducing your nitrates. Biopellets are a solid
form of organic carbon designed to slowly feed
denitrifying bacteria inside of a reactor. The pellets provide a food source and a place for the bacteria to grow. The pellets are tumbled heavily to constantly slough the bacteria growth which then exits the reactor and is removed via protein skimmer. This method is similar to carbon dosing but is done inside a reactor. Proper water flow through the reactor and a very efficient protein skimmer are crucial for this
method to be effective. Nitrate removal resin
is a recent advancement thanks to Nitrate FX from Blue Life USA which specifically absorbs
nitrate from your aquarium water. The media can be expensive when used for constant nitrate control, but it can also be
regenerated for multiple uses which helps combat the higher price. Regeneration is simple and
involves soaking the media in a sodium chloride solution. The media is very tiny, so
it is important to contain it inside of a media bag so
you don’t accidentally release the tiny beads into your display. A sulfur denitrator is
a recirculating reactor that houses a bed of sulfur media, below a bed of calcium carbonate media. By creating an anaerobic chamber inside of the sulfur denitrator, a colony of nitrate consuming bacteria is established on the sulfur media. The bacteria converts sulfur into sulfate and nitrates into nitrogen gas. At the same time, hydrogen gas
and CO2 gas are also produced which then lowers the PH of the
water inside of the reactor. To help offset the drop in
PH, a layer of calcium media is placed above the sulfur media, which will help increase the PH and also enrich the water with calcium and carbonates before
it exits the reactor. These sulfur denitrators
can be really useful for heavily stocked aquariums where extremely high
nitrates are always a threat. The concept was originally designed for waste water treatment,
and once established, required minimal adjustments. The only maintenance is
the periodic replenishment of media and cleaning of the reactor. Determining the nitrate control methods that are best for you are
all about you and your tank. The first priority for all
aquariums is prevention. Insure that you’re using pure
RO/DI water, do not over-feed or allow leftover food
to enter your filtration, and of course maintain
your filtration system. When nitrates are continually
a problem, only then would you want to consider
additional control methods. I have seen many tanks
running successfully on only live rock, and
I’ve also seen tanks running a larger refugium, algae scrubber, and biopellets all at the same time. Also, be patient. Many of
these methods require time to become established and
start reducing your nitrate. Something somewhat important
to understand about biological denitrification is that
the presence of phosphate is required for most of
these methods to work. Bacteria and algae are
living organisms that require carbon, nitrogen, and
phosphorus in order to survive. The lack of any one of these elements can limit the amount of
denitrification that occurs. For example, as macro algae
grows it consumes nitrates but also phosphate along with it. Once the available phosphate runs out the algae cannot grow and will
no longer remove nitrates. The same case applies
to beneficial bacteria. This case is rare in aquariums, but is certainly something
to consider if you’re having trouble establishing
biological denitrification or growing nitrate fixing algae. We have an excellent video
all about phosphate control and you can find a direct link in the video description below. Be sure that you follow
along with us here on YouTube by hitting that subscribe button. I appreciate all of you for watching and until next time, take
care and happy reef keeping.

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