Aquaponics in Africa

[Eco Owl]

Hi All,

I am new to aquaponics.

I have build a Flood and drain system using a 1100 liter tank which I sunk 2/3 into the ground and 4 Grow beds each measuring 2m x 0.5m x 0.3m. The grow beds are each filled with riverstone.

The system is a basic flood / Drain. the grow beds are fed for 15 minutes every hour. I takes about 10 minutes to flood the beds and this level is then maintained for about another 5. It takes about half an hour for the beds to drain and after another 15 minutes they cycle starts again.

To fill the grow beds uses about 350 liters from the fish tank.

the system was filled about a month ago, I started circulating a week ago and I planted seeds into the grow beds yesterday.

The water is quite cloudy from the riverstone (despite spending many hours washing it) but I have installed a cloth filter to remove the particles and hopefully clean the water.

I too the first measurements of the water today, the results being:

Temp: 22 deg C
Chlorine: 1.5 mg/l
pH 6.8
KH 6
GH 4
Nitrate 0
Nitrite 0

I have 3 questions:

1. I intend stocking with Talapia 8-10cm fingerlings. Given the 2m2 grow beds and 1100 liter tank, How many fish should I stock with?

2. The chemistry is confusing me, what adjustments do I need to make, and how, to the above levels?

3. I have purchased some Nitrosol Natural Plant Food which claims to be safe for animals, it is primarily made from bone meal. Is the safe to use to boost the plants? If not, what about a natural Kelp fertilizer?

I look forward to your suggestions / comments.

Thanks,

Eco