Backyard Aquaponics
A place to discuss aquaponics

This thread is being copied from another site, mainly because I can't be bothered writing it twice.

Let me be the first to say that I have no idea what I’m doing when it comes to aquaponics. But that’s not stopping me. I am learning as I go. I just hope I don’t kill too many fish and vegetables in the process.

When I heard about aquaponics a couple of years ago my first thought was that the fish wouldn’t have much taste. I didn’t know anything about it then, and still don’t know much, but I’d eaten farmed fish and thought it wasn’t as tasty as fish from the sea. But now I think aquaponics is a different kettle of fish, so to speak. It’s not supposed to replace the flavour of sea fish, it’s a sustainable substitute for sea fish. I’m hoping the taste will be almost as good too.

I guess the only requirements we had in the setting up of our system were that it not be too expensive and not look like a heap of junk sitting on the back verandah. This is where it will be located. As you can see, it's close to one of the water tanks, the green house and there is also a kitchen sink attached to that wall. Good for washing vegetables and fish before they come in the house.

O yay thats a big tank.

Naturally, when you think of aquaponics, you think of Joel Malcolm and his ingenious Backyard Aquaponics, so as soon as we decided to go ahead, I emailed Joel. We’ve now seen the DVD and almost finished reading the book and we’re ready to dive in.

As there are only the two of us, we’ve decided on a small system of a fish tank and two grow beds. The fish tank will hold 2600 litres of water, the grow beds have a capacity of 860 litres, but as they will be half full of gravel, their capacity is actually 430 litres. So all up the system will circulate 3030 litres of water. The water is rain water we’ve harvested from our roof and held in a water tank. The next size up for us would have been 5000 litres which I believe is the size of Joel’s system.

We thought about using recycled tanks and were offered an old tank on a property near here but it was rusting and had pin holes and we thought it might be more trouble than it was worth. We ordered new tanks from Foley’s Tanks at Woombye, phone 07 5442 1409. The fish tank cost $300 and the two grow beds $200 each. They should be here next week.

We’ve also ordered our first fish. Did someone say something about putting the cart before the horse? Hmmm, maybe we have but they’ll be here on Thursday. We got them from Sunland Fresh Fish Hatchery at Boreen Point. Phone 07 54853144. Our test fish will be 100 silver perch fingerlings. Price - $50 for 100. Here is a photo of the holding tanks we'll put the fish in when they arrive. We'll grow duck weed in these tanks also. You can see the aeration pump attached to the wall behind the tanks. These tanks have a capacity of 160 litres each. Please take no notice of the pink wall. I went through a stage of rendering and painting with Porters poisonberry lime paint.

We’re still undecided about the gravel we’ll use in the grow beds. It needs to be small – 10mm - have no sharp edges which would damage tender roots and with a kind of porous quality that will allow the beneficial bacteria to grow on it. I’m still trying to learn more about the relationship of the bacteria to the system so I won’t go on about it here as I really don’t know enough about it yet.

Other important purchases have been our two pumps. One is for the small open tanks we’ll put some fingerlings in and grow duck weed in. That one is small and cost $50. It’s a good quality German pump and it’s silent when running. We bought it at Mooloolaba Aquarium & Aviary Centre 100 Brisbane Road, Mooloolaba. Phone: 07 5444 2466. The main pump that will circulate the water from the fish tank to the grow beds will be a larger submersible pump. We are trying to get pumps that won't use a lot of electricity to run. Here is the photo of the pump we have now.

We bought two extra open tanks for growing duck weed and as a holding tank for finglerlings. These were $35 each at Bunnings.

I have always been silently critical of people who buy a slab of meat on a polystyrene tray and have no concept of that "meat" once being a live animal. I really admire the small producers who give their animals a good life and a humane death.

I realised I was doing virtually the same thing with the fish I bought. The thought of killing something made me cringe. But I knew that if I was to eat the fish and was responsible for its death, then I also had to be prepared to kill it. I have come to terms with this now and will knock a few on the head so it's not always H's onerous duty to be the slaughterman. I'm not looking forward to it, it's quite confronting actually, but if I eat the fish, I also have to do the killing occasionally. I intend to give the fish a really good life. I'm going to make their tank as "natural" for them as I can, give them organic food and play with them (if they let me). I know there will be some who turn their eyes skyward reading this, but to each her own.

The fish have arrived!

One hundred silver perch finglerings that have been raised on an organic fish farm with organic food. The cost: $50 for 100. I got them from the Sunland Fish Hatchery (0754853144) just north of Noosa but they were delivered here as the owner, Gwen, was travelling past this way today. Great service that! She really knows her fish and was the first person to breed Murray Cod in a dam. She is also into organic vegetable gardening when she has time so she might pay us a visit here.

Gwen advised that we don't use a galvanised tank for the aquaponics system as it will kill the fish, so H is going to the tank maker today to see if we can either change to colourbond or we'll have to paint the interior with non-petroleum bitumen paint. We can't use the rainwater in the galvanised tank either so we're lucky to have twice the amount of water in a plastic tank.

We had to quickly empty out the tubs we'd filled for them and refill one of them with water from the plastic tank and now they're settling in nicely. I've put in a couple of pieces of plumbers pipe for them to swim through and they have duck weed in there too.

Later today I'm going to start sprouting some grain for them. Gwen said they will eat vegetables and they need 30% protein to keep them healthy. We're buying some organic fish food today and we'll supplement that with vegetables and grains.

You can't see them well in this photo because the tub they're in is black. But I hope you can identify a few of them, you might see some towards the bottom of the photo and there is a tail disappearing into the white pipe. I'm not naming them.

H spoke to the tank manufacturer. The tank will be lined. The fish have had their first feed, there was one casuality, but the rest of them seem happy and healthy.

Our current tank is lined too so we can use that water. Phew.

Things are moving along quite nicely now. We hope to have the new tanks next week, probably Wednesday. H is busy constructing the support for the fish tank and the stands for the grow beds.

This is the base for the fish tank. It is made from treated pine. You can also see the first of the washed gravel in this photo.

The fish are fine despite a panic yesterday when I was told that at this stage, three meals and day plus morning and afternoon tea might be a bit too much for the fish. We have no pump on these holding tanks so the water is not being pumped through the grow beds to be cleaned. If the nitrite levels climb too high, the fish suffer and could die. Nitrite levels climb when the water isn't cleaned and the fish are fed too much. We filled the second tank up and put half the fish in it. I tested the water last night and this morning and it's all clear. We've been advised not to feed the fish again intil they're in their big tank. I wonder how long they can go without food.

We also had one jumper and we have to cover the tanks when we're not around. Luckily the fish jumped out while I was there staring at them so I was able to pick him up and put him back with no problems.

We bought some gravel to put in the grow tanks. This is the growing medium for whatever we plant. It has to be washed so all the sand and rubbish is removed. I've discovered that washing gravel is not a good thing.

I have a number of seedlings ready to be planted in the beds. I'm growing tomatoes, cucumbers, kale, silverbeet, lettuce and cabbages to start off with. I'll add more as I go. I really excited about this new way of gardening. I wonder how it will differ from organic soil gardening.

Thanks to everyone at the backyard aquaponics forum for helping so much.

that's some nice looking carpentry.

Just make sure there is no water contact wit the treated pine on the way back to the fish tank

that's it for now exept to add that the nitrites tests last night and early today were clear and the pH has remained at 7, so I think the fish have survived ok.

How long can they go with no food?

yep, I think we have that under control, monya.

A week would not present a problem with no food. You could float a couple of lettuce leaves for them to nibble on.

If the system hasn't cycled yet - you would need to watch your ammonia Forest, not just nitrite. It may be that there are no nitronomos converting the ammonia to nitrite yet. What is the ammonia reading?

I don't have a test kit for ammonia, VB. I'll have to get one in the morning. Is there any other way I could check for an approximate level of ammonia?

With new fish in an uncycled system its there, change out some water. 50 percent every day if you can't test for it. Then when you can read the nitrites do your water changes based on that reading. IMHO

I can do a nitrites test now, and it's clear. I'll move some water out now.