(upbeat music)
- You may never have thought about this,
but your food selection might very well be the reason,
why you've nailed either nitrate or phosphate,
and individually, one of these is stable in your tank,
but the other one is constantly rising.
This really hit home for me for the very first time,
as I'm monitoring the tank cycle of my own tank at home.
For months I'd been feeding this tank,
the lights are off,
and presumably there isn't a whole lot of nutrient uptake
from any organism in the tank other than the fish,
and the input is just what I'm feeding.
However, after a handful of months
of feeding the tank every day,
I test the nitrate levels to be five parts per million,
which for me is a little high,
but also in a range that most people would probably be okay.
But phosphate was a different story.
It was 0.5, which is a level
that almost everyone would find too high.
However, there's a couple interesting factors here
that five parts per million nitrate,
and 0.5 parts per million phosphate,
just happens to match
that 10 to one nitrate to phosphate Redfield ratio
that we talked about in a previous segment.
However, is that really desirable?
Well, that really depends on your goal levels,
specifically your nitrate levels,
because what you're about to see here,
is the disparity of why it's so hard
to maintain fairly low levels of phosphate
when you really don't care about nitrate as much.
For instance, apparently the food that I'm feeding
maintains about a 10 to one ratio,
meaning that if I had one part per million nitrate,
I'd have 0.1 part per million phosphate.
And largely okay for me.
However, if I let the nitrate go,
inevitably, the phosphate's going to scale with it,
and outside of a range that I feel okay with.
Take an even deeper, more impactful look at this.
Imagine if I had selected a food
that was five to one nitrate to phosphate,
meaning that when I got five parts per million nitrate,
I would have one part per million phosphate,
which almost everyone would find ridiculously high.
The inverse here is also true.
Imagine if I had selected a food
that was 20 to one nitrogen to phosphorous,
that means what I hit one part per million nitrate,
I'd actually have 0.05 parts per million phosphate,
which is close to most people's goals.
So here's the conundrum.
Most reefers do care about maintaining fairly low levels
of phosphate, similar to natural sea water,
because it absolutely
will slow down calcification and growth.
Probably more than you think
if you let it rise above that,
and also affect coloration.
However, less so with nitrate.
So many reefers just don't care about nitrate as much,
but in this case, if you think about the food now
as a ratio, if I let nitrate rise,
phosphate's gonna go with it.
So this is why your goals and approach matter.
If you're finding that either nitrate or phosphate
in your tank are independently rising
and the other one's okay, what you're gonna have to do
is play a little bit of mad scientist
to get one down over the other.
You'll have to pick a filtration method
that only removes phosphate, or only removes nitrate.
And there are chemicals like lanthanum chloride,
or phosphate E or GFO that will suck out the phosphate,
and probably the most popular method for that.
But I'm now reacting to it.
Option two, is actually just pick the right food
that matches the input for my own tank.
So which food is right for you, your tank, and your goals
will probably be a little bit of trial and error.
It's fairly likely
that many of the seafood options out there,
will likely follow that Redfield ratio,
be somewhere close to 10 to one,
if it came out of the ocean.
Not necessarily, but likely.
And everything else, who knows?
If the number one ingredient on it
is a terrestrial animal, or beef heart,
or corn, or wheat, or yeast,
really, it's kind of unknown, and you'll just have to see.
Now it'd be nice if we could just test the food alone
and figure out that ratio,
but it probably won't be as helpful as you think,
because there's all kinds of different organisms
in your tank that are uptaking nitrogen and phosphorus
at different ratios.
There's bacteria, there's corals,
there's algae, all kinds of different things in there.
And really what we're looking for here
is not mad scientist again.
We're just looking for trends.
So I'm not looking for a weekly pulse on this,
but more so like quarterly.
If every quarter or month I'm finding out
that I just can't keep phosphate down,
I can absolutely select a food with less phosphate.
Now we're perfecting stability more intelligently
rather than trying to correct for instability
with filtration media after the fact.
So if you see one of these elements rising
and the other isn't, try something new
with the inputs of the types of foods selected.
Now, none of the foods that I've run in to
have a clear list of nitrogen to phosphorous ratio
on the packaging, but what many of them do have,
it's a percentage of protein,
as well as a percentage of phosphorus,
which will get you fairly close.
So you can make an intelligent change
if you want to switch.
One specific note here is frozen food frequently
has a lower phosphate ratio, often dramatically so.
So if you're looking for less phosphate input
of the tank, frozen food might be the best bet.
One of the most overlooked pieces of this
is our stages of the tank.
How we feed, what we feed, and the right nutrient levels
changes with the age of the tank.
What's okay at six months is totally different
than it is at year two or three, or six or seven.
This is probably the most important thing
related to nutrients, and it's next.