A few days ago, I asked our social media followers what they thought we used our two new goldfish for, and got some amazing answers! Funnily enough, the inspiration for getting goldfish was from an episode of Peaky Blinders where there were goldfish in the water troughs of the racehorses. After looking up this intriguing practice, I found out it's a long standing traveller tradition to keep goldfish in horse bowls as they "keep the levels of hair algae down". I like to test things out for myself, so I'm yet to investigate this by calculating if I clean the trough less nowadays!
Most fish owners feed their fish the commercial fish food available in most pet shops. I was going to buy this, but first I checked what was in it. Unfortunately, like most commercial food items that are sold to us, it is full of unwanted chemicals. For example, fish food contains nitrates which actually pollute the water and help algae to grow (the exact thing I'm trying to reduce here! Nitrates are also one of the reasons that fish tanks need a filter). I didn't want any potentially harmful chemicals in the horse's water, so I came to the conclusion that, in classic Willowbrook fashion, I would have to find a sustainable alternative. I researched how people keep fish in ponds (and in horse troughs,) in an environmentally friendly way.
What I found
Goldfish eat a variety of vegetables and insects. We have lots of insects naturally in the house, so no issues in finding them on a farm! As for vegetables, goldfish can eat a surprising variety from kale to cucumber to peas. If there's ever spare vegetables suitable for them from our dinners, or Adam's vegetable patch, l put a small handful into their trough.
Otherwise, the resourceful fish eat the grass which falls in the tank when the horses drink from it, along with mosquito larvae and other bugs. It's beneficial that they eat the mosquito larvae, as the horses are often troubled by mosquitoes. The codependency of these two oddly paired species goes further: By drinking the water daily, the horses "pump" out the old water which takes out the ammonia from the fish's waste. As we have an automatic refill trough hooked up to our water system on the farm, fed by our well (which is not chlorinated), it refills itself and even oxygenates the water.
The Best Bit
So, I can leave the trough for days and the fish will be fed, their water filtered and oxygenated and there will be a few less mosquitoes in the field with the horses - all without me doing a thing! I do, of course, check them regularly to give them a handful of veg or worms on a particularly rainy or windy day when mosquitos won't be landing in their trough.
Another plus - the horses act as bodyguards protecting the fish from nosy cats and predators too scared to approach them! Much to the disappointment of our two farm cats.