Backyard Aquaponics
A place to discuss aquaponics

Hello from Greece,
as a new member i'd like to present you mine and my 2 friends' plan about building a
semi-commercial system in a greenhouse.It would be great if you shared your opinion about our system and give us your advices about it.
My system consists of:
1 Fish Tank1 10 m^3 buried in the ground where the only pump of our system will be.all the other water transfers will be made due to gravity
Water from FT will be pured to the the filter tanks which are:
1 Tank2 5 m^3 where the water will be filled with oxugen due to the waving surfaces of the water.
Water coming out of this tank goes to the other rechtangle filter tank3 5 m^3 where the biofilter of our system will be.I think of foam materials being in this tank where the ammonia will be thrown of the system and the majority of bacteria will live.As a result the water coming out of this tank3 is filtered and almost ready for the raft tank4.
Raft Tanks are 60 m^2 and 30cm deep making another 20m^3 tank.there will be an airpump blowing air in the water ,giving extra oxugen in the water.there will be growing 2.400 roots(mainly lettuce).And finaly the water goes to the Fish tank again,closing its circle
water pump:10.000 Lt/hr(water is making 3 cycles per day)
airpump:1800 lt/hr
fishes:rainbow trout(ideal trout temperature fits exactly to our annual average temperature)
1000 fish 200 gr each (when system cycles)
I am waiting to hear your opinion about my system.will it work?i am worried about the biofilter and the stocking density at present.is there enough fish for the plants?is there something i must add to my system?

Welcome George... I think you're our first Greek member... or at least our first member that's living in Greece anyway...

Hi rupe,yes i think i am the first member living in greece but i am hoping that there will be more.There are no Greek books or articles for aquaponics as this sector is tottaly unknown to our country.Even agriculture Scientists in Greece have little or no knowledge.So i want to spread the idea of sustainable systems that produce low cost quality food,to help people find a way out of the crisis in wich we are.i will not be saling any knowledge or equipment,just want to show people ways out of the crisis and a different way to live with low needs.I am in need of HELP to design my system.Any first thoughts about it?

Welcome GK good to see the fun spreading.

Diagrams and pictures would help us to comment on your system design but my first thoughts are to rearange your FT position. If you have a pump in the FT solids will get sucked into it and be pulverised by the impeller of the pump making it harder to filter out the solids. While some fish can handle quite high solid concentrations in their water trout really dont like them.

Welcome GeorgeKara

I made this diagram as a first plan for my system.The only water pump will be in the oxugen tank and have 7,5 m^3/hr flow rate.the other flows are made due to gravity and are constant.The water pump is working for 1 hr continuously and then it stops for 2 hours.
Fish tank startes with 5 m^3 of water
Oxugen tank startes with 6m^3 of water
Filter and raft tanks are always full.


i attach the diagram also .sorry but it is my first time uploading in a forum

this is the diagram

Hi George, welcome to the forum. Nice sketch. Will the "filter tank" also be used as a growbed? Why or why not?

Overall, it looks good to me, although I don't know alot yet. I think I would use more filter volume, to avoid overwhelming system with solids. This is just a guess. I am not sure how the raft tanks factor into the 1:2 fish to growbed volume ratios.

hi jdp
there will be 100kg of fish (500 fish 200gr each at start).this gives us a high stocking density of 20kg/m^3 and a low stocking density of 10kg/m^3
i am not sure about the volume of raft tanks they can support.
filter tank will use foam material to filter the water.there is a thought to add another filter tank with gravel(no plants in it) to have more solid removal
the reason i dont use the filter tank as growbed is that the system is already overweighted with plants so it will reduce the growth of plants.