With the nights closing in we really need good lighting in the poytunnel so that we can keep working on the aquaponic system in the evenings. After a fair bit of research I found the perfect solution – low-energy security lighting. We’ve now got two of these lighting the tunnel, they’re only 36w each but give the same amount of light as standard 150w security lamps, we bought them online from TLC for £17.99 each.

 I’m pretty impressed with them so far: they come on quickly, and throw a good amount of light .We’ve got them secured to the ridge pole of the tunnel so that they throw the most light possible – and here’s the result:

We’ve made some major progress on the Aquaponics in the last couple of weeks, and now I’m getting ready to start ‘cycling’ the system. This is what you need to do to build up the colonies of beneficial bacteria in the growbeds that will clean the water once we have added the fish. To minimise the risk to the fish you do this cycling ‘fishless’, by adding ammonia manually to the water. Once the bacteria are going well they will feed off this ammonia, turning it into nitrates for the plants. Without the bacteria, ammonia in the fish water would quickly reach a fatal level, so we need to have the bacteria well established before we add any fish.

We’re going to start cycling the completed side of the aquaponics system while I complete the plumbing and gravel-washing on the other sections, and here is the completed side:

Now you can see the plumbing all connected it hopefully makes more sense: The water overflows from the fish tank at the back into the dark grey pipes which feed each growbed. The water then slowly drains through holes in the bottom of the growbeds into the white return pipe, which returns it to the sump.

I’ve connected up the pump too. It’s quite an impressive beast:

What’s even more impressive is the flow from it – the pipe in the photo is 38mm (1.5″):

So now I just have to get the bacteria to build up and we’ll be ready for the fish – I might even start to plant some seeds in the beds while we’re waiting.

As my work laptop is currently a smoking wreck on the bench of our local IT support guys, I’ve had a bit more time to work on the Aquaponics system. And so here we are: the first growbed is ready. All the piping to it is cut, the standpipe and standpipe surround are in, and I’ve filled it with gravel.

I have to admit, that is a pretty good feeling – even though I now have another 11 small ones like this, and then 3 large ones to do. Pretty fantastic stuff really!

Not long and we’ll be planting, and adding fish.

Finally, after much work inside and outside the polytunnel over the last few weeks, we have put the polythene onto the tunnel. We only just got there – had a full-on Sunday getting everything ready and then doing it. We haven’t finished yet – one end needs more battens, and we need to put the doors back on. We did manage to do it though, and just in time – the first frost of the season was last night, and while everything outside the polytunnel was frosty, everything inside was just a few degrees warmer, with no frost. Not bad bearing in mind we only got the cover on at dusk, so it didn’t have much time to heat up yesterday.

Here’s what it looked like just after we had finished – showing the fantastic lighting:

Today we’ve started to put the completed growbed stands  in. The growbeds now all have drain holes in their bases and the drains are almost all in place. We’ve even connected all the sumps together (nice big 110 mm pipe). Now I just need to get the tubing and fittings for the drains and inlets and we’ll be ready to start the system up.

Here are some more pics of the growbeds and stands:

Steel & Timber growbed stand:

With growbed in place:

Showing the three linked sumps:

And a frosty growbed sitting outside the polytunnel:

Following last weekend’s adventures with timber (cutting the legs for the stands and the fish tanks), The steel rails for the top of the growbed stands is now here. Luckily it’s cut to size, so now I just need to finish the legs off, drill some holes, and assemble the things.

Easy

We’re making slow and steady progress on the polytunnel now. We had put off doing all the timber work while we dug the beds inside the tunnel, and got all of the aquaponics system ready. However, with the delay we’ve had sorting out the stands for the aquaponic growbeds we decided to get the timberwork all done and the polythene up. At least that way we’ll have somewhere warm to garden as the weather gets chillier!

So we had a good go at the timber on the weekend – building doors (one large at the back, double doors at the front), door frames, and the timber rails that go around the bottom to attach the polythene to. We didn’t quite get it all done – the rails still have to be attached to the bottom of the polytunnel – but we do now have doors, and door frames attached to the tunnel. It’s starting to look almost finished! While it’s taken us a while we haven’t had any problems following the instructions – good job by First Tunnels.

We’ve been a bit silent on progress on the Aquaponics recently. Not because stuff isn’t happening – quite the reverse! We’ve been so busy digging holes for the sumps and designing the growbed stands that we haven’t had a chance to tell you about it.

Here’s the hole for the large sump. It was only supposed to be 500mm deep but at the soil is so good and “easy” to dig I decided to take it down lower – to nearly 900mm. This should allow us to grow plants in the sumps as they’ll all get a bit more light.

And here’s the sump in place:

Having got a little over-keen on the digging for the main sump I then had to drop the other two shallow sumps to the same level. The’re not as deep though, so only about 400mm of digging for these ones:

And here they are, both in place:

Now I just have to connect the three sumps together and we’ll be ready for the growbed stands.

Looking back on it, digging these has been a labour of love. In a lot of ways I’d have been better off designing the system to have them all above ground. However my aim with this system is to get the most use as possible out of the space – so we’ll be trying to grow duckweed, water chestnuts, and possibly taro or wild rice in the sumps to give us true multi-level growing.

Maybe I should have just hired a little digger for the day. Or some Navvies!

As we’re getting close to having all the parts of our system in place I thought it’d be fun to have a look back at how our plans have turned into reality. It’s quite an interesting story in images:

We started off with the first plans for our large Aquaponics system

These went through lots of refinements to maximize the use of space and got to the current “final design” for our Aquaponic system

Then we got into the Eco-House and could finally start measuring up for the polytunnel

And then after one great weekend the frame of our Aquaponic polytunnel was up:

And then, after a weekend away and a bit of dithering, the Aquaponic fish tanks and Growbeds arrived at it started to look a lot like the Large Aquaponic System Plans.

Getting pretty close now! Just got to get the stands and plumbing done!

The aquaponics system is all coming together – the tanks and growbeds arrived yesterday. Here they are laid out in their final positions in the polytunnel, and luckily thay all fit! Now I just have to do a little bit of digging to sink the sump (the mid-size tank at the top), get the stands made that’ll support the growbeds, and do the plumbing!

We had pretty good weather on the weekend for the polytunnel and got it about as far as I’d hoped. All the metal work is up – on Sunday we added the corner reinforcement, door bars and the crop bars (those horizontal bars that we’ll hang tomatoes, cucumbers and squash from).

It’s looking quite impressive now – can’t wait to get the growbeds and fishtanks in!

And the gravel has just arrived – 5 cu. metres – that’ll be fun to shift in our wheelbarrow!

Follow our journey with Aquaponics here