Sunday 19 November 2023

Having a whole lot of trout...

...and having it in a fantastic place!

After our trip to the Quilmes ruins, we went to Champinan campsite in the hills above the Quilmes valley. Ismene and I were particularly excited as it would be our first time camping in a long while, since the Routa de las Lagunas in Bolivia to be precise!

After pitching our tents, Ismene and I ran around in the surrounding forest, making bows and arrows which I whittled beforehand with my whittling knife, and admiring Jorge's (the owner of the campsite) trout swimming happily in their tanks! The trout, as we were soon to find out were going to be a big part of our stay - from feeding them to eating them and even swimming with them - the fish were probably mine and Ismene's favourite part of the stay!

The most interesting thing about the trout - once we'd eaten ours - was the aquaponics system that Jorge was building. Aquaponics is where the fish and the plants work together as the waste (meaning poo!) from the fishes is used to fertilise the plants, and water can be recycled back into the fish ponds. The clever bit in the middle that makes this all work is bacteria.

To turn fish poo into fertilizer for the plants two steps are needed: Firstly, one type of bacteria consumes the poo (ammonia) and turns it into nitrites. Then the second step, or the second bacteria, consumes the nitrites and produces nitrates. These nitrates are what the plants need to grow, and the extra water goes back into the fish tank and it goes round all over again! It's like magic!

If you didn't understand that, here is another way of thinking about this: at the moment, Jorge has to give the trout fresh water from the river constantly. But this is problematic because there's a shortage of water at times, particularly because of climate change. What Jorge is doing is genius because soon the water from the trout tanks will go to water and fertilize the plants, and then as pure water, it will be pumped up the hill back to the fish tanks completing the cycle which is constantly on the go! 

Jorge showed us where the new fish tanks and the pump system he has planned are going to be. He also showed us where the tunnel for the pipe pumping water back up to the fish tanks is and how it will all work. He's waiting for funding to finish the work. It will then be used to prove the system in this area of Argentina and hopefully encourage local communities to build their own and have a sustainable and ecological food supply.

He also told us that he will plant totara reeds to help purify the water in the fish pools. Totara reeds are used for making houses, boats and islands, and they are even used as food, on lake Titicaca, the highest lake on earth which we hope to visit shortly (once we get the car docs - see below!)

In fact, this system is so awesome that I wanted to try it out for myself. Here is my plan: when we get back to England, I will get a small fish tank and a small plant (an aquaponics system) for myself (though with a guppy fish in it, not trout )! Does anyone from my class get the joke?

ps. We finally got the official car document we need to cross into Peru so we'll be making our way north very soon. Yayyy!


  1. hooray, you can move on! Did you observe any response to the election of Javier Milei? Lots of love, Sal

  2. Yes we were there for the election read my post