Cold water fish such as trout can be easily grown in winter. However, they struggle when the temperature increase above 22C. In this article I will share few tricks, you will learn how to keep trout alive in summer.
Oxygen and water temperature to keep trout alive in summer
When the water temperature increase, the concentration of oxygen into the water decrease. Hence, the fish have less oxygen available. A good way to help the fish going through summer is to equip your fish tank with an air pump. A constant supply of air during the warm season will ensure a saturation of oxygen into the water. How much air is enough? Trout like a concentration of oxygen close to 7mg/L . An oximeter will give you the exact concentration of air in your pond. Yet, you will do well even without this fancy equipment. all you need is to add a pond/aquarium air pump. enough to create fine bubbles but you don’t need a jacuzzi.
A flood and drain backyard aquaponics is composed of at least a fish tank/pond and a grow bed. Both of those parts contain water. We want to keep the water temperature cold enough. Hence, we must take the temperature exchange with the air in consideration. It is always a good idea to insulate the off ground tanks. Several materials can be used. Polystyrene is a common option. Now if you have the option to build an inground pond, you will benefit from the soil insulation. This technique is the most efficient and the most aesthetic. To improve the thermal inertia of the system I would recommend to dig deep. The deeper the pond and the more stable the water temperature will be.
It is obvious that a pond exposed to full sun will heat more than a covered pond. What is somehow less obvious is that the same fact is valid for the grow-bed. Indeed, the general productivity of an aquaponics system is dependent on the sunlight. The more sunlight and the more productive the system will be. However, if you want to keep “cold water fish” in a region with warm summers, you may want to find a compromise. You can position your system in a partially shady area to limit the quantity of sunlight. Another option is to use floats on your aquaponics pond/fish tank.
Feeding and temperature to keep trout alive in summer
Trout is a cold water fish and will continue feeding in relatively cold temperature. There pick of food consumption is between 16 to 18oC. However, when the temperature increase above 20C trout struggle to digest properly. So it’s important to decrease the food distribution and to stop feeding above 22C.
In conclusion the above are very good trick to keep your trout alive during summer. Obviously if you are in a very warm or tropical country they will be of no help. So make sure you will be able to manage the temperature, you may want to try the first summer with a very few fish only. If they survive summer, you can keep more the following years. Let me know how you go in the comments.