Backyard Aquaponics
A place to discuss aquaponics

Hi all,
i am George from Greece and i'm designing my second Aquaponic setup(first one is a small indoor 15Lt F.T. F&D system and has been running for 3 months).I'm going to build a 6m x 12m Greenhouse with some passive solar attributes.It will contain:
11.000 lt Fish Tank. 7m x 1m x 1,5m burried 1m deep
16 Ibc's growbeds at start with some future planns for expand
I will grow Nile tilapia during summer and trout during winter.I have spoken with an aquaculture professor who can give me tilapia and trout fingerlings.He also offered to help me with the aquaculture part of the system as far as he can.
The place where the system is going to be built is not connected with the national electric network so i designed a hybrid energy system to provide me the required energy.I had to pay more money to connect to the network than the money required to build the energy system.
I will come with more details and a drawing of the system later
I am very happy being a part of that forum.I have learned a lot till now and i am sure i can learn much more

I am waiting for the licences required for the GH and the setup at this time (bureaucrasy is a hard thing in Greece)so the only thing i can show and do is optimising the plann.
here is my plann

Looks good. Can't wait to see it complete.

Are you going to use timed flood and drain or siphons?

i will use a 11.000 lt/hr pump 150watt
http://cgi.ebay.com/NEW-EASY-PRO-STAINL ... 459wt_1139


The fish tank's capacity is 11,500 lt but i will use for my calculations only the 8.000lt,to have a ratio 2:1(16 ibc's:8.000 FT).the other 3.000 is extra water for better water quality for the fish and extra thermal mass for the Greenhouse.
the 8 ibc will be used as ther are,1m deep each.the other 8 will be cut to 8x 70cm deep and 8x 30cm deep growbeds
the perimetric wall perimetric the greenhouse is 1m height roof insulation panel.The north side has 2m height insulation panel
the vertical rafters will continue to the roof as the main skeleton of the gh but i couldn't designed it .

hi arbe.
i am thinking of using siphons.i am a bit afraid with the timer's malfunction risk

As regards the energy system i will use a qind turbine 1,5 kw wich is apropriate for low rpm
http://cgi.ebay.com/General-1500-Watt-W ... 6777wt_905
and the control panel from the same manufacturer
http://cgi.ebay.com/ALL-ONE-charge-cont ... 2811wt_905
and 4 batteries with total capacity of 600 Ahrs
as a suplementary source of power i will have a 6kva diesel generator running with biodiesel attached to a charger which will also be attached to the batteries in case of no wind.
The system needs 200Ahrs/per day so i will have at least 2 days autonomy
Here we are in wind zone 3-4 so i think that there will not even be a need of running the diesel generator

If you are going for the 2:1 system, you will either need a sump tank or you will need to run some sort of sequencing valve which will usually require a timer (going this big a good repeat cycle timer is a good thing and far more reliable than the little mechanical ones.)

Is the fish tank low enough for the grow beds to drain into it? Otherwise where are the grow beds draining to? Siphons need a little fall in order to work well.

hi TClynx
the 2:1 ratio or 16:8 in the system meens that there will be 3000lt of water extra in the fish tank.
the 12 growbeds will start to flood while the other 12 will be almost filled.
8000lt(growbeds) x 40% = 32000 lt of water in the growbeds needed.
the f.t. has 11000lt .11000-3200=7800lt in fish tank at this time.thats why i said i only calculate the 8000 of the 11000 .
I might be wrong but why i am here.
On the other subject i am thinking that i have missed that in the design,so i might re-design it with the whole fish tank digged,or i might give some height to the growbeds by putting them on some kind of structure .
i will also take a look to some timers and i will take in mind what u said to me to have a better opinion to answer u about that.
Excuse me for my poor english(education system in greece is a mess).

Your English seems to actually be better than some I know to whom it is their first and only language.

I'm not sure how by using siphons that you would ensure that one bank of grow beds was full when the other bank is empty, siphons are never that cooperative in their timing or cycling. If using only one pump and siphons you have to plan such that all beds might be flooded at the same time or all beds might be drained at the same time. There is always a chance that siphons might not fully kick in and leave a bed flooded and just trickling over the top of the siphon (pump needing cleaning can cause this situation on a regular basis actually.)

So with 11000 lt in the fish tank minus the 6400 liters only leaves about 4600 liters in the fish tank which could be rather stressful if you stock a heavy fish load.

I would suggest you do some searching on CHIFT PIST (constant height in fish tank pump in sump tank) or CHOP (constant height one pump) systems which might also offer you some flexibility in heights so you might do a 8000 liter fish tank and have a 8000 sump to handle flooding your grow beds or you might look up Rupe's Spider valves (indexing or sequencing valves) to be able to flood your beds in groups of two or three and be able to greatly minimize water volume fluctuations in the fish tank or allow the use of a much smaller sump tank for a constant height system.

I have a simple (no sump tank the pump lifts water to grow beds and they drain back to fish tank) with indexing valve 2:1 system in my back yard where I have 6-100 gallon grow beds and one 300 gallon fish tank and by using The Aquaponics Indexing Valve, the water level barely fluctuates in that system except if the power goes out. I get constant water flow back from the grow beds into the fish tank because they flood one at a time so there are always a couple of them draining. I use a repeat cycle timer so the little pump runs for 9 minutes and then is off for a minute and repeats that over and over so each bed gets flooded once per hour.

Hi George , I like your design, You mentioned "passive solar attributes" I know what it is, just wondering what temps you get around your way and what sort of attributes you will use

Momma used to say "Stupid is as Stupid does".

Hi George I can't wait to see your system set up! I have a quick question, what is your climate like where you can have trout in a greenhouse? I ask because I also have a greenhouse and I built thinking I want to do tilapia year round but now I am thinking I want to do trout over the winter. I was just wondering how you would do that with your greenhouse and what your climate is like. Thanks and good luck!

Tclynx,i now understand your point .i have decided to do the system like that after 2-3 months of researching in the forum.My first design was a chip system which when i finally started to find specific items costed to me 1/3-2/3 more money than this one.The main reasons are the cost of the fish tank which would not be burried(when digged simplier construction,less money).The other one is the fact that semi-burried has some kind of insulation or burried even better.
So the solutions i see are:
-making a bigger F.T.
-adding a sump next to the fish tank
-buying a timer
i have already seen the spiders that rupe and is a good solution too.

hi tea20,thanks for the "like".i haven't studied a lot about passive solar gh but what i understand is that by insulating the north side of the GH and by adding a big volume of water in this side you get some effects.I have read somewhere in this forum that i need in the north side a thermal mass of 15.000 for my 70 m^2 GH.
Another attribute is that the north side of the roof might be constructed from the insulation material too.That would be even closer to a passive solar GH than the uploaded sketch.
We have snow 4-5 times each year in winter with temps around 4-8 C ,mean value ,during december and january.In summer temp i think is around 25C mean value for 2-3 months.I just have moved here so these values are just predictions from the local people and some little research in the local university database.
I can be more specific in the future if u want to but i need to make some more research first.
hi Steveiscrazy,I think that the climate question u asked is just above answered.At first i was convinced that i should have carp year round by taking a look at the resistance temperature values of each species(carp 0-30 C).But i found that acuaculture professor that suggest me to have trout in winter and tilapia in the summer,but he mentioned that during winter we might have to heat the water for the trout as temps some times drop bellow 0 C.
hi dejavoodoo,old people always say wisely things
Thank u all for your thoughts,you really make me think more and more

I would think trout would do just fine through your coldest times even at below 0C temps as long as the water does not freeze over, which, with movement should be fine?

hi bndbear,
i believe that trout would be fine too.heating will be used only in some special conditions.
heating by compost is something that i have in mind and i already have tested how i can heat water in a tank in the middle of our compost pile!