Hi everyone,
I'm a 19 years old french student in agronomy, and I've been interested in hydroponic since 2010, when I builded 2 small DWC systems to compare mineral and organic fertilizers for a school project (turns out organic fertilizer doesn't work in DWC...).
In 2012 I learnt about aquaponics, and it seemed to good to be true, so I collected information about it, and in october 2013 I decided to build an aquaponic system with a friend in our IUT (university institute of technology).
We know that we won't be there next year, so we also have to write down how to manage the system and what has to be improved, hoping to transmitt the aquaponic virus!
We decided to put it in a glass greenhouse, and we already had some equipment to work with, since the IUT had an old hydroponic system used to grow tomatoes, and also tried to depollute rabbit manure in a phyto epuration system a few years ago.
(Since, our IUT experimental domain moved to organic agriculture, the hydroponic system is no longer in use, and the rabbit manure is now pile composted.)
So we had these two 1300L (340gal) tubs, meters of irrigation pipes, we bought 2m² of pozzolan (volcanic rock), 2 IBC, cutted them in half, added tap on the top parts.
Then a kind professor of physic lend us a 800L/h pump and we builded it!
So 2600L (690 gal) of FT, 4m²/2m³ of GB.
The irrigation isn't really conventional, as we are using a buried perforated irrigation tube with regulators (just the first part of dropwise, 1mm openning, 9 times through each of the growbeds, i'll put a picture tomorow) and they tend to clog over time.
The two 1300L tubs are connected to the pump entry with hose and T pipe, and the water is then pumped to the GB.
The pump is working 30 minutes, then stop for 45, during all day, and only five 15 minutes cycles during the night.
So the GB and the roots are never immerged but only have water running through.
The plants doesn't seems to mind but maybe that this isn't optimal?
In the long term we'll have to buy new pumps anyway, as the one we are currently using needto be returned to our professor.
You can see the 45 (8-10 cm) goldfishes we are currently using :
We wonder if this is enough?
Feeded every 3 days with commercial fish food. In the future we want to feed them with raised daphnia or equivalent, maybe trying an Mealworm larvae breedind, using wasted bread from the university restaurant...
The NO3 is actually around 50 (because we used ammonium nitrate to lauch the nitrogen cycle... and we only got the fishes a few weeks ago but some spinach are there since october, so we used the old hydroponic fertilizers at the beginning...
)
We don't have any aeration for the moment, but we will try to get some one day...
We had some problems with aphids, so we searched for ladybug in the domain, got 15, and put them on the damaged spinach :
The orange blobs are ladybugs eggs, they have now hatched and the aphid population is under control!
Even if the spinach are uneatable now, we won't have further problem with aphids
.
The plants currently in the system are 15 small tomatoes, 30 badly damaged spinach, 10 or so pumkin seedlings, and 7 maize seedlings. (the picture is a bit old now, i'll get you up to date ones tomorrow)
We were wondering if a solid removal filter would be useful?
Something a bit like that :
And maybe even a biofilter, just a water tub with high aeration? Even if we have an adequate GB, it might be useful.
I'd also like to have you opinion about adding calcium in the water, as fish food doesn't contain nearly enough.
Is it recommended, indispensable...? I was thinking of calcium chloride, to add Cl- ions beneficial for fishes altogether...
And as we aslo have large stock of monopotassium phosphate, epsom salt (magnesium sulfate), CaNO3, and some other fertilizers, do you think we shall use them, in very small quantities of course?
Anyway, thank you for reading, (I hope that everything is understandable) waiting for your thoughts
!
Backyard Aquaponics
