Hello sustainable growers.
Today, we're going to talk about filtration in aquaponics.
So you probably know that I'm specialized in small scale growbed aquaponics such as
the ones I have behind me.
So they are composed of mainly a fish tank and a growbed on top of it.
For the small scale setup most of the time, we don't use any filtration, any specific
filtration.
So we will see today that there are two types of filtration.
There is the mechanical filtration and the biological filtration.
We're going to talk about it but when we design a classic growbed aquaponics setup for our
backyards or small-scale setup everything is ensured by the growbed because in the growbed
we got some bacteria but we got also a lot of rocks, a lot of media, and this media is
going to basically act as a mechanical filter and as a biological filter.
So by mechanical filter we mean basically cleaning the water, retaining or filtering
all the big particles of organic matters.
So you know that when your fish are in the water, you feed them.
They're going to eat this food, the fish food, the fish pellets and they're going to also
release some into the water.
So what we use in aquaponics mostly for the nitrogen cycle is the ammonia.
So the fish is going to release some ammonia into the water by their gills when they breathe,
by the pee when they pee in the water, and also by the poo.
So there are three ways of how the fish is going to release the ammonia.
Also when it dies its body is going to break down as well and it's going to release some
ammonia into the water but this point is not very important in aquaponics because what
we want when a fish dies we want to get rid of it, remove it from the tanks.
So what we need to focus on is the ammonia that is produced by the fish, released by
the fish through the gills, through the pee, and the poo.
For those three types of ammonia you got two of them.
The pee and the gills they are released into the water so they are not solids.
You can't really touch them.
They are diluted into the water and they go directly into the growbed where they
are transformed, thanks to the bacteria, into some food for the plants.
Obviously,. it starts with ammonia and then it produces some nitrites and then some nitrates
and the nitrates are the source of fertilizer for the plants.
Now for the poo, for the fish poo, it's a bit different.
The fish poo is going to go through the pump.
A part of it is going to be broken down and basically diluted into the water in very,
very thin particles, but some big particles are going to be also present in the growbed.
And those big particles they're going to form basically, well big quantity of organic matters
and sometimes they're going to be trapped in the growbed for a while.
If you got a good ecosystem some animals are going to break it down and they're going to
help to dilute it in the water but sometimes it’s going to clog also the media.
So depending on the type of media you have and the size of the media, for example here
we are working with scoria, 7 millimetres.
So scoria is a volcanic rock and therefore it's got some very, very tiny holes inside
and if you work with clay balls as well, that's the same thing, they are porous but the holes
are very small.
If you release big particles of organic matters so a lot of fish poo, with the time, with
a few years, it may clog the system.
So when the system clogs, you got some areas of your media that don't have access to the
oxygen anymore because there are so many basically mud, organic matters around this media that
it doesn't have any access to the oxygen of the water or of the atmosphere.
So in this case it turns anaerobic.
You got the fermentation and then it can generate some problems in your aquaponics setup.
So in aquaponics, what we want is to keep all the biomass and all the media in aerobic
conditions.
And to maintain those aerobic conditions, obviously, we got the bell siphon that is
going to allow us to work with a flood and drain system but also we will have to maintain
our growbed every two years or three years or five years, depending on the type of organic
matters you have.
We will have to clean that media.
So we will have to move the media and making sure that all those big organic matters that
are present in the media and all the roots of the vegetable and all those things that
can clog basically the system, we're going to move everything and we're going to allow
all those particles to be flushed away from the system.
So it's going to allow us to stay in aerobic conditions.
So you have to do this every, you know, as I said every few years, depending on your
system, on the way you feed your fish, on the temperature and a lot of things.
Now, if you use a mechanical filtration a mechanical filtration is going to help you
to retain those big particles before they enter the growbed.
So we got different types of mechanical filters.
In aquaculture they are very much used.
Some of them are passive and some of them require some power.
So today, I want to focus on the passive mechanical filters.
They are very interesting because obviously they don't cost any money.
They are free.
You just have to build it and then you install it and it doesn't require any specific source
of energy.
And they can basically return all those big organic matters which means that only the
clean water is going to go through your growbed and through your system.
All the fish poo that are big particles they're going to be captured into this mechanical
filter.
In the mechanical filters the two that are very much used in aquaponics at the moment
are swirl filter and the radial filter.
So there are two types of filters, the swirl filter basically works with the centrifugal
force.
So here we got the sketch of a swirl filter.
The swirl filter is going work with the rotation of the water.
So the idea is to have the water coming into a drum, thanks to a pipe.
So here you got the pipe number 1.
So the water is coming into this pipe and here you see there is an elbow at the end
of the pipe.
So here the water is turning.
Once it's in the pipe the water is turning and all the particles are going to stay because
of the centrifugation.
They're going to stay on the extremity of the drum, basically, close to the walls of
the drum.
And then they're going to fall down because they are heavy and they're going to sit on
the bottom of the tank.
So all the particles are going to fall down and you're going to find them here, while
the clear water only is going to be able to access to the extremity of the pipe number
2.
It's going to fall into the pipe number 2 and it's going to go to the next step.
So this is how a swirl filter works.
So you can see that basically into this drum you're going to capture all the solids down
the bottom and the clean water is going to come through and it's going to go to the next
stage.
Here we got the same thing but it's a view from the top.
So you can see that the water is coming from the pipe number 1 and here hop, it rotates
and therefore all the particles are going to settle down and they're going to touch
the side of this swirl filter, so the sides of the drum, basically the walls.
And they're going to slowly fall down and they're going to settle down while the water,
the clear water is going to stay in the middle and it's going to fall on the surface inside
the pipe number 2.
So here we capture all the solids.
So that’s how a swirl filter works and that's basically one of the most simple filters to
build if you want to build it by yourself.
The radial filter works in a different way but it works basically with the speed of the
water.
We break the speed of the water and it helps all the particles to settle down.
So same thing we got a drum and all the particles are going to settle on the bottom of the drum
and the clear water is going to be able to go to stage 2.
So here you can see what we call a radial filter.
So this filter is going to have the same purpose as the swirl filter.
So both of them are what we call mechanic filters so they're going to mechanically or
basically, physically retain the particles.
So basically, they work with the weight of the particles so the idea is that the particles
are heavier than the water, and if you put them in a place where there is not much movement,
not much water movement, they're going to settle down.
So here the idea is to have the water that is coming through the pipe number 1 basically
inside the drum, and then it comes to almost the surface and here then the water is going
into a pipe that is just a little bit larger than the incoming pipe.
It's like probably three times the size of the pipe that is taken to come.
So basically here now the water is falling down but the speed of the water is slightly
decreased right because there is more surface.
So you know that the speed of the water, there is a constant like it means that the water
flow is equal to the speed multiplied by the section.
So the section of the pipe here you see that the section of the pipe is way larger than
the section of the pipe inside.
So basically when the water comes here up it starts to decrease in terms of speed and
when the water is out of this pipe here, it arrives into this big tank, the speed completely
decreases because the section of the tank now is huge, right?
So the water flow here is very, very low, right?
So the water flow is always the same, right, inside the thing.
The water coming is always the same so the water going into this pipe is always the same
but what I mean here is that the water flow is constant but the speed is going to decrease
dramatically here because the section is huge.
If you compare this section here to the section there and to the section here there is a big
difference.
So here the speed of the water is almost stopping and therefore all the particles can just settle
down slowly to the very bottom of the tank while the water, the clear water is going
to rise very slowly to the surface of this drum and therefore fall down into the pipe
number 2 and go to the next stage.
So you see the difference.
The swirl filter is working with rotation of water.
Here it's working just only with the gravity and with the sections of the pipes.
So the idea here is really to stop the speed of the water, while in the swirl filter, we
still try to maintain a nice rotation.
Here we want to have the water very, very quiet.
Now this radial filter is very efficient as well but you need to have this pipe here.
So most of the time we fix this pipe to the lid or we put a piece of metal or something
here on the top to basically maintain this larger pipe above the water.
So I recommend both of those systems.
They are really, really good.
They are both very useful to retain the particles to avoid to have some organic matter that
fall into your growbed.
So now why is it so important to have those types of filters in aquaponics?
Well, it's very interesting I think because first it's going to allow you to clean you
growbed a bit less you know.
You may have to clean your growbed, maybe if normally you would have to clean it every
two years, maybe you will be able to clean it every three or four years if you have a
mechanical filter.
Also all those bacteria that are living in the growbed you know with time they form what
we call a biofilm which is a good thing, but then the biofilm can become very thick and
it can also clog the media.
So even if you got a good mechanical filtration it's not going to avoid the maintenance of
the growbed.
So from time to time you will have to move your growbed, move the media and basically
clean the media.
But the filters, the mechanical filter is going to basically capture all the solids
and therefore it's going to minimize the quantity of ammonia that is going to be generated for
the system.
So it can have an advantage.
If you want to put a bit more fish in your system by putting a filter you basically minimize
the quantity of ammonia that's going to be present in the setup and therefore, you will
be able to capture them and to use them for a classic garden.
So you will be able to siphon or to collect the particles that are on the bottom of this
drum and you will be able to use it as a fertilizer for your classic garden.
So it's going to be an excellent fertilizer so you don't lose it, you don't waste anything,
but at the same time, you're going to maintain a lower concentration of ammonia and nitrate
in your aquaponics setup.
So if for example you have a lot of fish and not enough growbed, having a filter is going
to help you in this way.
It's going to decrease the quantity of nitrogen in your setup.
So it's a really good point.
Now, there is another type of filtration.
It's called the biological filter.
So this biological filtration is basically exactly what we are doing in the growbed is
giving a good environment for some bacteria to grow and basically to transform the ammonia
to nitrite and the nitrite to nitrate.
So by doing so, we're going to basically add a media into a big drum with a lot of movement,
thanks to some aeration.
So we need an air pump here and the air pump is going to blow some air on the bottom of
this drum and while the air is going to the surface, it's going to create a movement,
so all the pearls, all the media that is inside this drum is going to be in movement all the
time.
So all the bacteria that are living here are in full aerobic conditions, it's full of air,
plenty of air and also because there is such a movement, the pearls of media are always
shocked one against each other.
So if there is a biofilm of bacteria that is growing on the media, once it's reached
a certain size, it's basically with the shock it's disconnected and it flows away.
So this type of biological filter doesn't need any specific maintenance.
So that's a really, really interesting point.
So today with this video, I really wanted to present to you all the different types
of filtration that you can have, I mean the general ones, so mechanical and biological.
And now if you want to go further and if you want to build your own swirl filter, I designed
a training, a real training to help you to build your swirl filter so you can access
this completely free training and you don't even have to put your email.
You just follow the link below.
You don't have to do anything really.
I'm not capturing any emails here.
I just want to help you to build your filter.
So if you build this filter, again it's going to help you to be a bit more comfortable if
you want to put a bit more fish in your setup and to manage a bit better the quantity of
ammonia, nitrogen that you have in your aquaponics setup.
And also it will allow you to capture the solids for your classic garden.
So you will have a source of fertilizer for your classic garden.
And finally it's going to allow you as well to have a bit less maintenance in your growbed
so you don't have to clean the growbed every two or five years.
It's going to extend the frequency of the maintenance in the growbed.
So don't forget.
Just click on the link in this video and you will have access to this free training.
Again, you don't have to put your email.
So it's just a click and then it's a step by step and you just follow it and you will
be able to build your own swirl filter at home.
So obviously, with this video you still have access to the six-step process to build your
own aquaponics setup which is also a free training that you can have access by the description
of this video.
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I really hope to see you soon and I wish you a fantastic success with aquaponics.
Have a good crop!