Backyard Aquaponics
A place to discuss aquaponics

Hi All,

I work in aquaculture and have had a few enquiries from people over the past couple of years about aquaponics and i always thought "id like to give that a go someday" and now i am.

Started off reading alot on here and other forums and decided i liked IBC's. After a bit of hunting around i found independent oils in Burnie willing to sell them for $50 each so off i went for a trip and got 4:

Now they had hydraulic oil in them, but from what i could gather this was the best deal i was going to get. I found some in launceston for sale from Tas petroleum near macca's in invermay for $180 each and had motor oil in them, i nearly laughed as i walked out. But that is the nature of the beast down here. I tried a cheese factory that seemed to have quite a few out back and they said no they use them and food grade are rare as hens teeth.


So i chopped the top off them, gave them a real good karcher out and then scrubbed with detergent, then karcher again, then bleach and then karcher again and then i think detergent again and then karcher again. They seem clean as a whistle, could lick them.

Because the minister for war and finance wasnt impressed with the whole idea i was forced to place it all beside the fence out of the way. Here i have the 3 tanks layed out with growbeds ontop. Just need to bury the sump a bit to get my fall.

Digging in the sump was turning into a real pain in the a$$. The top inch of soil is good, but below that its infertile, hard and full of rocks and bricks almost like they used construction waste to fill my backyard. I bent my mattic blade severely trying to work it and crowbar was hard work that got nowhere fast.


just some of the rocks that came out of the first inch or two

So what else do you do when your wife is already angry at you for wasting time and money, hire an excavator!



Starting making really good headway straight away with the excavator, paid for itself in about 10minutes a couple of nice boulders.

But then i hit some rocks that were huge.



Spent a good hour trying to get this big baby out, maxing out the hydraulics and trying from every angle and nearly putting the excavator on her side a few times.

Then i tried a rotary impact drill and made very little progress so in the end i just had to move the sump maybe 20cm from my original design and it just fitted down inbetween two big rocks. neighbour since told me they had to use explosives to build my house the rocks were that bad.



with the sump inplace i sorted out some plumbing, added a blue barrel swirl filter as i reckon ill be pushing my luck with fish loads.



I set the whole thing up and filled with media(small white rocks) and went on a three week holiday and when i got back they had all severely sunken into the ground on the side the growbed is sitting on. So i had to jack it all up level again and concrete it to hold it in place.

planted out my first bed with broccoli, brussel sprouts and asain green and some lettuce seeds. 18-4-14
At this point the system has been cycling for about 5 weeks with about 10 rainbow trout of about 70g, no water tests done yet.

Added 80 or so rainbows to bring total to around 100.


1-5-14
After 2 weeks nothing has really grown except my lettuce planted by seed. I figure that i must have been too harsh on the transplant and the seedlings are still getting adjusted and thats why the seeds are going great. Have also planted second bed with caulli flower.
I tested the water at this point to check and the ammonia was 0.79, nitrite was 0.25 and nitrate was 10-15 and ph was 7.1 so i thought things looked fine and it hadent quite fininsed cycling yet.

15-5-14
4 weeks, things are finally starting to grow and seemed to be taking off quite well, but they are showing signs of iron deficiency.

the iron deficiency shows the worst on the brussel sprout leaves.

I havent done a water test in a few weeks, so ive ordered a master test kit and an iron test kit for the times like now where i have 4 days off work and need to test my water. For now i went to bunnings and got some manutec chelated iron and added about 30g and sprayed some of it directly onto the foliage, been 24hr and havent seen improvement yet. I suspect that either the ph has gone up somehow or the algae and bacteria coating the tanks are stealing all the iron. Been planning to paint the tanks to try cut this down.

Thats my little set up so far. I know im probably short on growbed area to fish tank volume and i plan to add more growbeds away from the shade of the fence and possibly a NFT strawberry tower thingo.

I can't believe your wife did not let you use explosives to get the rest of the rocks out! Until you add more grow beds, I would stay conservative with the number of fish you stock. Give your system some time to get established. Obviously in aquaculture, you try to get the most fish in your tanks as possible, but in Aquaponics, growbed volume, or biofilter volume, determines how many fish you can stock. Eventually someone will have a reliable table for how much growbed volume can support how many of each fish species. But until then, it is best to play on the conservative side.

Love the mimicking of natural rice patties on the slow design

Did you use river rocks only on the top layer>? Hows the water look

Best things I found when starting out is bok choy, cos lettuce and kale

The rocks you see fill the entire bed. I wanted to use scoria but it was $240 a metre down here because it has to be brought over from vic. I asked the guy if he has had others doing aquaponics/hydroponics and he suggested i use this stuff as that what others had used. It was quite cheap, i think $65 a metre, but it was very dirty. I would say nearly a quarter of it was a really fine sand/dust off the rocks being ground together. Took me about 6 hours to wash a metre of it by hand in a river out near my work with a sieve. In hindsight i probably should have just forked out for the scoria, it would have taken less washing and been alot lighter, the growbeds weigh heaps when full but i guess such tightly packed together small rocks should provide good surface area for nitrifying bacteria.

Even after my immense washing efforts the water still got quite cloudy at the start, but quite clear now, can see the bottom of the tanks easily.

You'd be far better off with the media you're using than scoria. Scoria wouldn't be all that much lighter when it's absorbed the water and what you have would be a lot easier to plant things than scoria.

Plants seems to be greener now with no veins visible anymore, so id say the chelated iron has done its job. Did some water testing tonight anyway and got:

pH: 4.5! - how on earth i was getting iron deficiency i don't know.
Ammonia - 1.5mg/l - cant even find a chart to work out the toxicity at 4.5. even at ph 6 im safe as houses.
Nitrite - 0.185mg/l
Nitrate - 52.6mg/l

Suprisingly my biofilter seems to be working, which is wierd, i believe they dont work at all in such acid condition.


Added two teaspoons of sodium bicarb to bring it back up to 5.8 for now, we use sodium bicarb at work but ive since read its not a good idea in aquaponics because the sodium builds up. So ill get some potassium bicarb tomorrow from bunnings and raise the ph a bit more.

You might chuck some shell grit into a stocking and steep it in your tank. It will act as a buffer to keep the ph from crashing.

My bunnings doesn't have potasium bicarb grrrrr.

Anywhere cheap to purchase online?

Hey Gav, just start pumping the feed into the trout and you should be right.. Seems strange that your pH crashed that much in only a week, did you do a second test?

You sure they dont?

i couldnt find it to start off with but then realised its a fungicide, so found it in the kill stuff section as apposed to the additives.

i think it was about 4 weeks since i had checked the ph, i checked it when i first put the media in and it was about 7.2. I thought the media might have a bit of limestone mixed in and would buffer around 7ish so didnt worry about it until recently. I checked it about 5 times with a calibrated ph probe to be sure.