# Aquaponics – Electrical Circuits

Date:  Jun 17, 2016

Why do me and the kids suddenly doing so much electrical projects recently?

Because we wanted to help mommy to enhance her aquaponics farm.

And now here is the problem:  The fish poo poo waste water is pumped up to the top shelf where you probably need to “hold” the water for a while, before it is fully drained down so to make the plants have the chance to do two things…

1. Absorbed the nitrates and nitrites from the fish poo poo waste water.
2. Clean the water and let it pump back to the fish tank.  So that the fish get fresh clean water.

So, how do you hold the water for some short period of time and then let the water flow back to the system?  By doing so, it will optimise the Aquaponics system.

So, the man in the house put on his thinking hat, with the help from the boys…

We come up with this simple circuit.

Again, when we deal with Electrical Systems, we must always warn “Electricity can kill you!  Please handle with care!”.

We will use Raspberry Pi (either a 3 or zero) to control the relays, and hook up a solenoid to control the water flow.  As simple as it is.

And let’s see how it works!

The python scripts will control the relays.  When it is supplied with power, the solenoid open up the valve.  When the power cuts off, the solenoid turned off the valve.

Of course, when we deal with relays, we need to make sure we do not supply too much current or voltage and worn out the relays, so, the final design must comply to the correct circuit designs by adding resistors.

If you see your kids have little interest or curious about something, don’t hesitate to make it a full blown project, and let them participate inside the project so that they can learn some real life lessons instead of learning only from books.

They will love it!

Ever since then, Jay Jay and Kay Kay has express huge interest in electrical circuits.

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