Backyard Aquaponics
A place to discuss aquaponics

Great project and good workmanship

At first I thought you where building a big fish tank! Looking really nice. Is there a reason it is sunk in the ground? Might get flooded but I guess you thought of that. Can't wait to see what you are going to put in there...

The passive solar greenhouse doesnt need to be dugg down, however its more than welcome to insulate it from the ground. The freeze barrier is down in 80cm-s here, which means that the 80cm-s can freez in hard winter! So if you have a perfect passive building the heat can still get out through the earth.

Ok than why is it "sunk"?

- I dont need a permit form the local goverment if its not higher than 3 meters.
- Digging it down helps to be little bit warmer in winter, and cooler in summer.
- This way I can raise the growbeds, and dont have to "sink" the sump to the ground. I have to expalin the reasons, but befor that we go fot the flooding.
- Groundwater is prety close to the surface - the highest I experienced is about 90cms - my floore is ~15 cms higher than that. I wount be flooded from below. Heavy rain wont jump the doorstep, I calculated with that when designing. Even if it does, it wont get into the system. If the system brakes - worts case scenario - at the pipe that connect sumps, I will have about 700l of water on the floor thats ~30cms of water. This case the fishtank stays full and aired. I only have trouble if the fishtank it self leaks. So I dont fear flooding.

Back to the remaining open question: Why digging so mutch instead of sinking the sump alone.

In hot climates sinking the sump and/or growbeds, and/or fishtank into the ground helps keeping your system cooler in the summer heat. This would be cool for me as well, but on the other hand I have a relative high water level in the earth. Eath is a good insulation when dry but if it ist wet its rather conductive cause of water. So lets imagine I burried the sump, and got higher ground water level in winter (which happened this year) the earth water level raches the sump and suck all the precious heat out in hours. This would cool down the whole greenhouse and cancel the whole winter growing. I dont know what woulf the fish do on cooling tham down by 10-15C in an hour, but maybe I dont even wanna know it.

Basicly I could bury the sump, but I would have to superinsulate it against heatm and ground water. Digging down the greenhouse keeps me without surprizes, keeps the local government away and its easyer to maintain.

Also side benefit that the coldest air flows down to the bottom, so the growbeds and the plants are not on the coldest place (the bottom).

I know it was a littel longer, but that was a good question!

This is what Im building:



Find out more about me, climate, system: http://www.backyardaquaponics.com/forum/viewtopic.php?t=9056

This is what Im building lazy to click edition

Passive Solar Greenhouse:
Sized 3,6m x 6m, height 3,6m, dug down 0,6m to the ground. The ground helps the smooth ups and downs in weather, and height of 3m above ground also means that I need no permit from the local government to build it.
South facing windows from double layer 10mm Policarbonbate all other sides, and roof insulated. Brick wall in ground also insulated. 2000 liter (530gal) of solar water tank on south wall. Passive air ventilation windows. No heating, no vents!

Aquaponics:
CHIFT PIST system from IBC tanks.
FT: 1000L (264gal)
ST: 2x 400L (105gal) (One of them can be operated as fish tank as well)
GB: 9x 300L (79gal) Affnan siphon
Media: 16-24mm river stones
Pump: Used heating pump, 3000m2/h (800gal/h)

Greens and fish:
Vegetables that I planted in the dirt garden are also fine with aquaponics.
Wels Catfish (Silurus glanis) – nice fish, love tanks, quick growing, tasty = perfect.

Ok one more update and I've done for today

News about fish:

- Molj is in (http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=2496)! We will share fingerlings and experiance. We'll be the "Pioneers of Wels Catfishin in aquaponics "

- Our supplier turned out to one of the top guys in researching intensive keeping and breeding carnivorous fish in Hungary. Pike, catfish, perch and zander are his specialities.

- Privatly he is the importer for Skretting fish feeds.

- He gave a higher price or fish, but its still bareable, I tried to bargain a bit without success. So price will be 0.50 USD /fish. I asked for a second offer, which will include shipping and the feed for the first two month.

I asked him about ingredients of feed and feed rates, and got valuable info.

He mentioned that he has a feed rate calculation for catfish. It calculates the quatity of feed from, gross weight of fish, temperature and feed type. Also by adding the catfish specific conversion ratio of digestion, they calculate Ammonia output to design the size of filterint in aquacultures. I'll get that information, we need it! An excell file would be great help.

When:
Breeding depends on weather, so the earliest date when we can get the fingerlings is end of may. I need to be cycled by then, and Molj need capr recepies as he is on carp now.

Hmph. I'm jealous. Here we need permits for buildings with foundations too, regardless of size. So if I built your passive GH, I'd need that permit.

You do beautiful work, zsazsa. Did I say that already?

Im having a pause with the AP because of final rushes for deadlines at job. But this easter weekend my brother will be back home and I hope we cam make a big impruvement.
I want to finish most of the wood work adn insulation.

So next week would be time for metal roof cover, and polycarbonate glazing.

I also have to buy the IBC-s early next week, because the fishtank can only go in through the uncovered hole frame on the west side. All the other "holes" are not big enough.


Here is a question:
My planned growbed media is riverstone, but I see on severeal systems that they use some kind of mixture.

lavarock+gravel --or-- gravel+ hydroton --or-- riverstones+hydroton

I need ~3 m3-of media, riverstones, gravel and hydroton are easily available, but there is a huge difference in prices. Hydroton price is 3x of the Riverstone. If I would make it riverstones in the bottomhalf and hydroton on the top. What are the adventages? Does it worth the aprox 2,5 times cost?

Is the back wall made up of stacked up 20 liter plastic drums filled with water? Does it matter where they are placed within the greenhouse? I think I should start filling all the 20 liter containers I can find and stacking them in my greenhouse wherever I can find a space for them.

- Yes! Filled with water, they are the thermal mass.

- Yes! On the north wall, with roof, and south wall angle designed according to your latitude. Because in winter the sun hits tham, while on summer they are in the shade.



- This would certainly help reduce thermal fluctuation in the greenhouse, but for the passive solar behavour you need water tanks insulation and design to work together.

More info on passive solar greenhouse (what, how, why)
- University of Missourihttp://aes.missouri.edu/bradford/education/solar-greenhouse.php
- PassiveSolarGreenhouse.com http://www.irisherbal.com/psg/content/whybuild.html
- Cheyenne Botanic Gardens http://www.botanic.org/Solar_Energy.asp

Following this with interest. Looking good.

Lot of work done, carpentry is almost over. I will make a video show arround tomorrow till than here is timelapse.

Very cool! I am on the lookout for 20 liter plastic containers!

Hi!

You wanna come to a sightseeing toor? Ok, lets go!
(The camera was my mobile phone. I was a little over excited, and made a lot of noise holding it, next time I'll do better. ).




Also got some pictures of the back side what the webcam doesn't see:

Great video

Can not wait to see the next instalment!