- Nickel is a metallic element with the symbol Ni
and the atomic number 28.
It's one of only four elements that are magnetic
and it's often used in alloys,
for example, in the stainless steel
that's probably somewhere in your tank right now.
It can contaminate the sand and the dry rock
that we might use due to groundwater that seeps through it,
although I think that's pretty rare.
Hi guys and girls, I'm ReefMan,
and his is a deep dive into nickel,
its effects on our coral,
and how to get rid of it in our tanks.
Now, as I mentioned, nickel is a metallic element
that's almost never found it its raw form in nature.
The only place that you're likely to find it in any volume
is gonna be meteorites where it's often found with iron
because both of those are actually produced in supernovas.
That's right, it's produced when stars explode,
which is just kind of cool.
Nickel is a pretty benign element.
It only really reacts with things
if it's been powdered into a very fine particulates.
And because of this, nickel is used in a lot of alloys
and it's mixed with other metals
and then it's used for coins and also to plate things
and it just generally prevents corrosion.
Now that's not to say
that it can't leach out of these things
in our saltwater tanks though, it can,
and it does show up on ICP tests,
like these Triton test here.
So, though our use of nickel as a pure metal
is relatively recent, there are records of nickel
being used often confused with copper
as far back as 3500 BC.
In our reef tanks, nickel contamination
is often the result of something rusting
usually something that you bought
that was built as stainless steel
but maybe it's not the highest grade.
There are many grades and types of stainless steel
and not all of them are gonna stand up
to the harsh conditions
that are found in our reef aquariums.
There are actually even reports that things
like stainless steel tongs causing a spike in nickel
even when they're only used for feeding
every couple of days.
In that particular case, the person ran a Triton test,
and they found 593 micrograms of nickel per liter of water.
That's a very high level that as we're about to see
can cause issues with your Acropora corals.
There's a paper that was recently published
in the Marine Pollution Bulletin titled the
"Effects of dissolved nickel
"and nickel contaminated suspended sediment
"on the scleractinian coral, Acropora muricata".
There is a link down below,
check it out if you're interested.
And in the paper, the researchers
are really interested in finding out
if there is an impact on the reef building corals
from nearby nickel mines and then the sediment
and stuff that washes down off of those mines
into the water in the ocean.
Normal seawater does contain some nickel
but it's very small, only about .09 micrograms per liter.
And near the mines, it can actually be as high
as seven micrograms per liter, so is that an issue?
That's what they wanted to find out.
Studies have shown that Acropora larva
are impacted by nickel,
but that's not so relevant to our tanks.
We usually don't spawn Acropora
or deal with their larva in our tanks.
Full-grown Acropora are known to start having bad effects
due to nickel at high levels.
Anything over about 200 micrograms per liter of water
given at least a few days of exposure.
Conversely, even tiny elevations in nickel
might actually be positive.
For example, a 3 1/2 micrograms per liter
has been shown to stimulate the use of urea
as a carbon and nitrogen source, which of course,
then boosts photosynthesis and calcification,
and you have healthier faster growing Acropora.
This study in this paper wanted to explore specifically
the impact that various levels of nickel
would have on Acropora muricata
because it's such a common reef-building coral.
They also wanted to know if sedimentary nickel
washing off these mines could affect corals differently
than dissolved elemental nickel.
Now, the team studied Acropora growing in labs
with zero, 200, and 400 micrograms per liter
of dissolved nickel to chloride hexahydrate.
They also studied sediment that they contaminated
with various concentrations of nickel
using the same compound.
They looked at whether or not the coral bleached,
if it lost any tissue or maybe had bare skeleton,
and also the effect on the algal symbionts
that lived within the corals' tissues
like dinoflagellates and things.
There was significant bleaching in the corals
that were exposed to the elevated dissolved nickel
at both 200 and 400 micrograms per liter.
They also noticed that even if the coral
didn't fully bleach, it lost a lot of color.
These effects began only a few days after it
being exposed to the nickel, so they weren't immediate.
The coral actually absorbed the nickel from the water
and accumulated it within its tissue,
and that contained, and that stayed in the tissue
for longer than they were adding it to the water,
and of course that means that a spike in nickel
in our tanks can have long lasting effects,
even if we clean up and remove the source
and reduce the concentration of nickel in the water.
This symbiotic algae that live within corals
actually collect more nickel
and other metals like it than the coral itself.
We think that perhaps this algae
might be acting as a protection for the corals
and it absorbs the damaging metals
to protect the overall coral that they call their home.
I do encourage you to check out the paper below,
it's linked if you want more details
and there's a lot more information in it
that I went into in this video.
So now that we know for sure that nickel levels
above about 200 micrograms per liter
are likely to cause bleaching
and other long-lasting problems with our Acropora,
what should we do about it?
If you just got an ICP test that shows elevated nickel,
the best then you should do first
is just look around for the source.
Look at anything in the tank that might be rusting,
things like algae scraper or magnets
that might be inside your vortex or other pumps,
even just a little smear of rust
is enough to get those elements into your tank's water
in surprising concentrations.
So once you've addressed
where you think the nickel is coming from,
the next step that I'd recommend is water changes.
Do them frequently, maybe even every day
until you've lowered the amount of nickel
that's in the water.
Things like Raufoss and Cooper-zorb
both absorb metals like nickel,
so they're an option that you can use
to help clean the water as well.
Both of these are going to be more sensitive
towards phosphate that could be in your water as well,
so bear that in mind, and you might need to end up
replacing them faster than you otherwise normally would
to keep them active against metals like nickel
and that's because as they collect phosphate,
they're gonna collect less and less of the other metals
which in this particular use
is what you actually want them to collect.
So, good luck.
It's never fun to get a surprise
like elevated nickel or tin or these other metals
back in your ICP test results.
Just work through it methodically though
and you're gonna make it.
None of these are gonna have long-lasting
irreversible effects that is gonna nuke your whole tank
and it's not gonna be the end of your career
as a reef keeper.
I hope you found the video interesting.
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I will see you next time, have a fantastic day, bye.