Backyard Aquaponics
A place to discuss aquaponics

Photo date: 8 September 2013

Photo date: 6 October 2013


I’ve started this barrel system just over 4 weeks ago. I’ve learned a lot about aquaponics in this short time.
The jam tomatoes are doing great. The Swiss chard is struggling, I think it is getting too much sun.

Test results so far.






Should the nitrates reading be zero at all???

Nice barrel
At only 4 weeks in its not uncommon. But it looks like there is some.

Thank you Nat! It is your barrel system that got me hooked into APs. My girlfriend and I are currently busy with a 1000litre IBC system. I intend to use some of my barrel system’s water to “jump start” our bigger system’s cycle.

I've decided to keep our little barrel system and I am planning to expand it. During my search for barrels I came across some nice open top barrels. We are currently using these open top barrels as nurseries for some carp and blue tilapias. We had about 60 small banded tilapias in one of these barrels which I transferred to my boss’ farm dams last week.

The carps are for our bigger system and the blue tilapias are for my girlfriend’s father’s dam. Unfortunately we’ve lost some of the blue tilapias it seems that they are not that hardy as the banded tilapias.

I had a brain wave the other day for a 3 barrel system using these open top barrels while I was busy cleaning one of them. But I can only put it to the test once we are finished with the bigger system.

I recently installed a 12V 4W light bulb underneath my barrel’s GB. The barrel doesn’t get enough light due to the isolation I installed around the barrel. So I installed the light bulb, rather than to take all the isolation off, cut another port hole or two in the barrel, risking contaminating the water with plastic shavings etc.

The light bulb is powered by a 12V 7A lead acid battery which is charged during the day by a 20W solar panel. I feed the gold fish only once a day which is usually at night time and then I switch the light on so the fish can see the food and I leave the light on for the reminder of the night until the following morning. The light also helps me to inspect the bottom of the tank, the pump and to see if all the fish are ok.

Your light might also attract insects at night, extra free feed...

Now that you mention it earthbound: I’ve noticed some moths etc. flying around the porthole at night when light is on. I never really checked if they end up in the water though. We had a grass termite problem a few days ago and I’ve caught a few of them and fed it to the goldfish. At first it looked like they didn’t know what to do with these “live feed” but they soon discovered that they can eat it.

I'm cycled at last!!!!
pH 7.8
Am 0
NO2 0
NO3 0


It took 4 weeks and 5 days. Unfortunately, I had my first dead gold fish today.
I have 5 jam tomato plants and 4 Swiss chard in the barrel. The tomato plants exploded in size the past week or so. Can’t wait to harvest our first jam tomatoes in 2 weeks or so.

Found another dead goldfish in my barrel system this morning. I did a quick test for pH, Am and Nitrites. The pH was 8, Am 0 and Nitrite also 0.

I came across Gran from WA's system where the topic came up about air volume = water volume. (thanks Rupert)
I’ve set up my pump’s timer to run from 6:00 to 18:00 and then 2:00 to 3:00 with a stand pipe in the GB. I calculated that the little air pump that is providing air to an air stone in the barrel’s 150litres of water only produces only about 74.9 litres an hour. We had extremely high temperatures the last few days with the tanks water reaching temperatures of as high as 24°C. Another lesson learned I guess?

Remember that the warmer the water gets... the less capacity it has to hold oxygen....

24C.... not a lot of air.... not a good combination... even for goldfish...

Bear in mind the reference in Gran's system was related to Trout.. and/or other Australian fish....

Which typically are much more oxygen demanding than fish like goldfish... and Tilapia....

Yup. I've noticed that she had trout in her system.

I got 20 Carp for our bigger system. Will try other species of fish once I got the hang of things.

Thanks again for the advice.

I'm going to set the timer tonight for more flood and drain intervals or maybe I must just run the GB CF.

It's been a while since I've posted anything. Like I've mentioned in Gran's post: I’ve lost all 10 gold fish over a period of a month and most of them I found dead with their mouths open. I’ve double checked and tested the water quality and the Ammonia & Nitrite readings were zero and only got a slight reading on the Nitrate side. I’ve checked all the dead fish’s gills and it was normal. I have a small aerator in the barrel and I was running the pump 24/7 with the GB CF.

I’ve noticed that I was losing a lot of water a day, and with 5 almost fully grown jam tomato plants in the GB it might be an overkill for the barrel system’s capacity? Also I’m not too sure how much oxygen plants can use via their roots?

Something started to tell me that my problem is oxygen deprivation plus high water temperatures which are making things only worse.

The gold fish were immobile most of the times staying at the bottom of the tank only a few of them were swimming around etc. and the ones swimming around were actually the ones that stayed alive the longest.

I've lost the last one about 3 days ago. I've done a complete water change and cleaned the pump 5 days prior the last and final goldfish death. I’ve also taken out the pump’s filter because I’ve noticed that it gets clogged very fast and all this clogged material can’t be healthy for any fish.

So Saturday, after a lot of thinking what to do with the barrel system and what caused the demise of my last goldfish, I’ve decided to give pee ponics a try and delivered the first “load” that morning. I’m healty and is not on any medication at the moment, so why not?