But if any year is one to grow avocados using the power of fish - yep, you read that right - 2020 is the one.

The school's year 10 agriculture class has put together an entire self-contained aquaponics system in the school's farm area, constructed nearly from scratch with recycled materials.

Several students explained the system they researched, deigned and built themselves which is currently home to 150 silver perch and a couple of goldfish.

The waste from the fish - both fish poo and ammonia - goes through a system which separates fertiliser from liquid waste, with the latter flowing through gravity-powered plumbing into garden beds.

The beds are a biological filter, with fired clay balls providing a garden bed of sorts for leafy greens, which will be upgraded to avocados and tomatoes.

Recycled coverings will keep the frost off and the heat in, while the water heads out a siphon when the water level hits a high level, when it's fed back into the fish tank using a pump.

The pump's currently electric, but the class is hoping to switch across to solar panels in the coming weeks.

"Every time we come up to the farm we have to test the pH, ammonia, nitrate, nitrite levels, they went in on Saturday and they've nearly doubled in size in a week," student Hugh Mackillop said.

"It's just kind of a new way of farming, people have done it over many years, it's filtering up now and people are starting to hear about it now."

He said it certainly wasn't expected from his agriculture class, but wasn't shocked it could be done in Orange - the system doesn't work with saltwater.

Not at all really, all has to be freshwater fish. You can't have everything still in the ocean.

His classmate Imogen Jenner said it had been "exciting" seeing the project come together.

"We had a lot of times where it wasn't working, we had to take the balls out and clean them a lot of times," she said.

"We started at the the end of last year and got straight into it. It's a good experience seeing it how it works."

She said having the whole class involved was a dynamic mix.

"It was very interesting seeing how different minds worked together to get it done and it was really good bonding."

Teacher Sarah Eyb said it had been as much a journey for her as for the class, as she admitted she knew "nothing" about fish farms and aquaponics when they began.

"We all researched it and the kids understood it before I did. Hughey was saying 'it's working like this' and I'd say 'nope, I still don't get this'," she said laughing.

"They've been amazing. These kids have owned this process, they're smarter than I am.

"I love all my classes but this class is a bit special. You all look after each other, they've all got different talents and they come together to use their particular talent.

"We took this on and once we started I saw a friend and they all thought I'd gone mad but they got into it."

The end goal for the class is to have smoked trout eaten with veggies grown in the filter, with trout to be brought in over summer, and with students only in year 10, there was still plenty of time to fiddle and try new projects.