In this article we will talk about trout, tilapia, lettuce, sunshine. We will see together if you have all the knowledge in aquaponics.

First question: is there any scientific proof of water gains in aquaponics?

It should be remembered that one of the main advantages of aquaponics is to reduce watering. But is there any scientific proof of this reduction? Is it 30%, 90%, 60%? The answer is no, there is no scientific proof of these water gains. On the other hand, there is a body of indices which tell us that compared to traditional agriculture, the water must be around 85, 90%. And maybe you can ask yourself questions like how much are we earning compared to permaculture which is also supposed to drastically reduce watering needs? It's simple, we have a saving of 60% of water compared to organic farming if we compare organic farming and aquaponics. Scientific proof no but water gain, yes.

Second question: what is the ideal sunshine for growing lettuces?

Lettuce is often favored in aquaponics. This is mainly because it is easy to grow. It doesn't need much, just a little bit of nitrates. So what is the optimal amount of sunshine to grow lettuces?

There are two answers to this:

• The minimum duration to have a very acceptable growth of lettuce is 14 hours of sun.
• And to optimize the growth of lettuce, your sunshine will have to be between 4 and 6 p.m.

Third question: what are the functions of the adhesive papers in your greenhouse?

You have surely already seen in hydroponic aquaponics videos or even traditional greenhouses, small sticky yellow anti-insect papers. But then, what are the two functions of this paper?

The primary function is to catch insects and the second advantage is to be able to easily determine what type of pests we have in our greenhouse.

Indeed, when we enter the greenhouse we find a lot of information there. Visually we see leaves, we see the aquaponics system which is the floor of the greenhouse and the walls of the greenhouse. We can also see some insects and pests there, but it is very difficult to judge the amount and the type of pest you may have.

Then we come to question four: are we going to talk about food? Is as much fish food needed per square meter of culture with tilapia as with trout?

It is important to remember that the sizing of a culture tank has nothing to do with the volume of water in which the fish swim. According to calculations made by scientists, we give on average between 60 and 65 grams of food per day and per square meter of cultivable land. Finally, it should be noted that for tilapias, it is hot water.

So, if we are moving to live cold water fish such as trout, then you will need to halve the weight of food you will feed your fish per square meter of trout culture. Typically you are going to be at 30 grams per square meter per day.

Last question: what maximum variation of pH and temperature can the fish support in 20 minutes?