In this video I'm going to show you exactly how to calculate the correct pump for your
hydroponics system if you interested in an aquaponics system check out the video right
here for those calculations now in a hydroponic system we can move much less water than in
an aquaponics system let's do the calculations so we will discuss the different systems first
and then we'll do a combined calculation now this is the nft system and nutrient film technology
system we have got a thin film of water running at the bottom of this pipe and it circulated
there's two things that you must calculate in your pump calculations the first is your
head and the head of your pump is calculated from the lowest level that the water can go
in your sump up until the highest level that the pump must lift water and that's your
total head for this system we will talk about friction in the pipes just a little bit later
the next thing is your floor rate your flow rate in a system like in nft systems is 10
to 25 L per hour you'll see this is much slower than for instance and aquaponics system because
in the hydroponic system we've only got our solution and nutrient solution that we circulate
and there's no nitrification process happening so your slope is 2 to 4 percent that equates
to 2 to 4 cm per 1 m that means if you've got one from there till there then the amount
that it must fall is 2 to 4 cm so let's move on to the next one is a vertical growth towers
in this case we've got three vertical growth towers again the head of our pump is from the
lowest level in the sump till the highest level that the water must be lifted and that
will give us our head and now the floor in these Towers again 20 to 25 l per hour so
for every single Tower you need to be able to deliver 10 to 25 if you go for the lower
end and you've got three Towers and it means if you've only got these three Towers in your
system your total volume that you must shift is then three times that 10 which is 30 litre
per hour the next system is a deep water culture and you're floating rafts will be on top here
again your head from the lowest level that the water can go in your sump in your system
and then to the highest point that the water must be lifted please remember that the highest point
is not the start of your grow better highest point is the highest point that your pipe
goes up and then maybe down into your gro bed so that's your highest point that will give
you your head for your systems and the flow rate in this case is calculated at least
your grow bed once per hour so if this is 100 l grow bed then your flow rate in this system
must be 100 litre per hour then we've got our flood and drain system and you can see
your Media here you can see your bell siphon again your head from the lowest point that
the water will go in your sump till the highest point that you can lift your water that's
your head and then again your flow rate is equal to the volume of your grow bed please
pay attention that in in a flood and drain system you've normally got grow Media in here
it may be expanded clay pellets or gravel crushed rock any type of system that you've
got there any type of Media that you've got there and that media also take space in your
grow bed so if this is 100 litre grow bed it's not to say it will take 100 l
because of the space that the grow media also take in the system it can
be typically have 30 litres but you have to do that calculation easy way to do that is
to take one litre cup put your grow Media in and then throw water in till the top then throw
the water out and measure that and you can do your calculation according to that alright
so yes our total system that we going to an example on
you see you've got three vertical Tower you've
got a nft system you've got a flood and drain bed and you've got a deep water culture bed
your sump is 4000 l
so let's start with that the first thing you'll vertical Towers there's
three of them and we took 20 l as the flow amount that we going to select their so 3 * 20 will give
out that 60 L per hour for our vertical Tower then we've got our nft system it's only one
of them in this case at 20 l per hour then we've got a deep water culture which is one
of them and you can see the volume of this is 1000 l
so it's 1000 l per hour then you've
got your flood and drain system and the water amount in your flood and drain bed is 500 l
so it one time 500-litre that will give us a total of 1580 l
for the system our head
is calculated only once for the system from the lowest point in this until the highest
point where you lift your water that will give us our head in this case 1.8 m
please
remember that head is only calculated from the lowest to the highest point and you don't
consider anything in between so that's our head who said we must compensate for friction
in the pipes and I do that by adding a 20% to my head so if the head is 1.8 m
I multiply
that by 1.2 to add that 20% so my total head in this case is 2.16 metres
now here are two pumps
there's a curve for one pump Curve for another pump on your vertical axis you've got your
pump head and on your horizontal axis you've got your flow rate it means that one will
represent 1000 l and 2 will represent 2000 l so we've calculated are required head as 2.16 that's
around there and we must deliver 1580 ll so at 2 m around here if we go here we will see
that this pump will only be able to deliver 1000 l
if we go over to this pump we will see
this pump will be able to deliver 2000 l and if I only only had a selection between these two pumps
I will take this one always make sure your pump kan do more than what is required that
will compensate friction in your pipes may be more than the 20% so and rather take the
higher pump in the in this case now I just want to show you one or two things here
this is a magnetic coupled impeller pump you will see these pumps normally does not have
a very high head so if you've got vertical towers in many cases they will not work as
a few pumps from these manufacturers you can see the model numbers here the power that
they consume their heads out the maximum head that they can deliver this certain l per hour
at so another thing that's important is the economy side of your pump maybe you will get one
pump that at 200 W and 7 m can give you 8000 l other one may be only used 150 watt
for that same amount and head so please have a look at the economy side if you select a
pump as well you also get variable frequency Drive pumps they were the variable frequency
Drive is built into the pump these days and that will also make an enormous amount of
difference in the power that you consume know that many of these pants will run
24/7
on your screen right now there are links to videos that may help you in your journey
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thank you and bye-bye