Backyard Aquaponics
A place to discuss aquaponics

we need to add "rock" to the list of AP hardware. I also used them ontop of siphons

hehe! & honey bucket lids.

I cable-tied shadecloth to the other 4 GBs ... but I think I prefer the honey-bucket lid & rock method better - I currently have a shortage of honey-bucket lids however.

I haven't done an update for a while.

I have been harvesting LOTS of Pak Choy, some beans (butter & purple), snow peas, rocket. Dwarf Marigolds have done well. Lettuce has been a miserable failure.

Growth is slowing. Plants are only getting morning sun (if it's not cloudy) as the house shades the GBs after noon-ish. I knew this before I started, but I didn't have any better locations to setup AP.

The weather is getting colder too - I am concerned that my SP will not survive a cold snap. I have been trying to think of a way to heat the tank using passive solar - poly pipe, heat exchanger & a pump - but I can't find an appropriate heat exchanger (for a reasonable cost). Worried that passive solar won't do much when I need it most anyway. ie. during a cold snap.

I've read mixed reports about what temperatures SP can survive - anyone care to contribute an accurate value?

Today I discovered 2 frogs in one of the GBs! Does anyone know what type of frogs they are? They looks similar to Green Tree Frogs, but I am not 100% sure.

It's getting cold.

scottie,,Confirm that is a green tree frog,and a bloody nice one.

I wouldn't think your SP's will die in Sydney weather,but they will certainly go off their food as temperatures drop, no eating=no food=no growth=no poop = no vegie growth. A visciuos circle.

How easy would it be for you to insulate your tank? Top , sides ( the most important).....,,,and bottom should be insulated if possible.

At this stage I'm still experimenting ,but an insulated tank with heaters that run on your
off-peak electrcity looks like the easiest, usefull / cost effective method.
Check your last electric bill,what where your off-peak costs per KW/h.

My uninsulated ( but living inside) , aquarium is about half a cubic meter in volume ( 500 litres) , it stays toasty warm with a 300watt heater .
Lets assume ( yeh I know never assume) , that we have a 1 cubic metre of insulated AP tank,,so say need 500 Watt submersible heater . Even if said heater runs 8 hours a night consumption is 4 kw/hours.On my supply costs that is about 25 cents. So monthly cost around $7.50.
So for less than $7.50 a month,your fish are happily growing at maximum rate,eating at maximum rate,poo-ing at maximum rate so your vegies are growing at maximum rate.
Seems like a bargain to me, especially since there is no friggen around with solar this , wind powered that and all the associated costs.

Total cost for this system,,2 X 250 W submersible heaters ( $20 from ebay delivered to your door). Power outlet $10,,hooking it into your off-peak supply ( zero if you've got a sparky friend,,it's 15 minutes work) and say $30 for wire and conduit).

Better still get a funny tomato grower and power will be free just a a slab to hook it up [only joking]

seriously though, and i think Food&fish will agree, a two species approach works well. Silver Perch grow and feed well during the summer and survive over the winter while you have RAINBOW TROUT that grow during the winter and can be harvested before the summer.

everyones happy

Heaters work in a small system, bu I think heating my 4000l of water and 2400l of growbeds might be a little straining on the pocket.

Dual species AP FTW

Agree steve , that would work very well depending on your climate.
Here in Sydney,near the ocean, trout would only get a 3 or maybe 4 month growing season before dying of heat,,,and no I'm not going to connect my beer fridge into a system A line must be drawn somewhere !!!


Never , ever interfere with a man's beer supply.

We mut have special trout in WA, they seem to grow fine over a winter

You might be surprised chappo.

Outback,,check youroff-peak electric rates.Could be cheaper than you think.
Pumps to the grow beds probably better being off at night,so discount them.

The other worry here is temperature shock,,tank and fish sitting at say 25 C,then pumps turn on , in themorning and gravel sitting at say 10 C,, 3 short pumpings in the first hour or two of the morning should get around that one.

chappo, rainbow trout are at more than edible size over a 4 or 5 month period!

as OBOz said, if they can do it in WA then you can do it in Syd!

If you have a 4000l system with 400 fish of varying sizes, that water is going to need to be turned over at least a couple of times a night.

The whole idea of AP is to be more ecological, I dont see how running 1000w of heaters when it is not needed (stock the right fish for the season) is helpful. I can see the point of doing it maybe for a month just to get the fish over the line, but not 5-6 months.

Silvers and barra in summer, trout and silvers in winter, no extra heating needed.

Yes, agreed ,,if these WA trout are happy at up to 21 Celsius , I can give them an 8 monthgrow out if tank is buried,,,food for thought.

Way cool! Now I just hope the Green-Tree-Frog-eating Green Tree Snake that lives next door stays away.



That's ok. I'm happy for the system to slow down over winter.



I could probably insulate the tank (currently holding 3000L), but the GBs are outside & just suck all the heat out of the water every time the system cycles.