In the back garden of my small terraced house in Wiltshire, UK I have a fish farm.
Rainbow Trout and European Perch. I am growing fish and fresh vegetables.
Aquaponics UK. Trickling water and sunshine. Leaks, wet feet and cold hands!
Along the way I get distracted by the food I grow and cook. People I meet and places I travel to.
These photos are of a part of my system I call the shelves. They face north and sit in the entrance to the shed. One hour direct morning sunlight on a good day. In the winter I can roll down a plastic curtain to keep the frost off.
I knew this would not be the most productive area. However it did allow me to increase the media in the system and play with winter crops.
Last November I planted small brassicas and they survived. I then transplanted to the main GB and we are eating them now.
I knew that additional light would be required.
I fixed a 20 W LED fixture above the bottom GB. To be honest no major improvement. When the filters above overflowed I removed it on safety grounds. I then saw some very cheap waterproof fittings on E bay. £7 each, 10 w per unit. At the same time as I installed these I added a RCD safety device. Now this was 10 W per shelf.
These shelves are part of my,’salty’ system so the choice of Samphire to plant in them was easy. This is a perennial so I was prepared to be patient. Growth to date has been disappointing. I stuck in a few watercress plants and a few sacrificial lettuce seeds to help combat the slug/snail problem I was having.
No surprise all plants faced the light at the front.
With the RCD now in place about a week ago I moved the two 10 W units onto one shelf and brought out the 20W unit for the bottom shelf. These run on a timer 9-21.
As you can see from the photo some of the watercress is now sitting vertical.
It has responded to the increased light source.
Now these shelves are not in the best position but in a south facing window with a small LED boost it could be promising.
A reliable NFT system was therefore high on my priority list.
Vertical expansion would also allow me to maximize on summer crops.
Some things fell into place immediately. NFT requires constant flow so an additional dedicated pump was essential. Flow rates of one to two liters per minute so only a small pump required.
One condition I set myself was to use only readily available UK household plumbing parts.
Just to recap. NFT or near film technique requires just that a, “Film” of water. Say 1 to 3mm deep.
This means, ‘round pipes are NOT suitable’
Using round pipes of various diameters is a tried and tested method that works BUT I think it is better called, ‘Shallow DWC’
So the choice of 6 cm square line drain pipes was easy. 5cm holes cut at suitable interval perfect fit for net cups and a one centimeter gap at the bottom.
I use 22mm pipe for water supply. This will connect to a readily available four way manifold. Each of the four outputs are standard 10mm push fit. 10mm push fit ball valves on each allows individual control.
You can seal the open ends with a standard 90* bend glued into place. I found push fit end caps on E bay which with a little bit of silicone work well. Cheaper too.
The next step is the water outlet. Here I used 20mm electrical conduit bulk head fittings. The standard 22 mm bulkhead profile is just too high.
Plastic washer cut from old milk bottle seals it well.
NFT requires super clean water so, in addition to the system filtration, I slip a plastic pan scourer under the water inlet. Ten for a £1. They also act as a spreader and help reduce pooling.
A few kilometers south from my home the Kennet and Avon Canal wends its way through the Vale of Pewsey.
We were moored up for the night but the grandchildren were restless. I gave them a long wire rake and told them to dredge for treasure in the mud alongside the mooring.
Canal beds were traditionally constructed from clay. This was trodden by workers to form the watertight base of the canal. It was called “puddling” Think treading grapes!
i say workers, but in reality it was probably the wives and children of the ‘Navies’ or “Navigators” who built the canal who trod the clay.
The local pub is called, “The French Horn”. Tourists, who inquire about the brass horn on the wall are told of how the prisoners from the Peninsular War were forced to construct the canal. French survivors from the battles at Salamanca, Badajoz and Cuidad Rodrigo. Reality is they were professional highly skilled Irish Navies.
Picks, shovels, wheel barrows, some horse power and sweat built this amazing, “ Linear water feature” A LWF? No! Its a F****** canal.
Standing on top of the sixteen lock flight at Devizes. The Caen Hill Flight stretches before you in all it’s glory. It takes the Irish to dig a big hole!
Apart from various junk the grandchildren dredged up dozens of fresh water mussels.
Larger than sea mussels they soon filled a bucket.
What do we do now Grand father?
Well, of course we purge them in fresh water!
Possibly the impatience of youth.
Probably the inability of the adult; not to elaborate.
When can we look for the Pearls Grand father?
Two hours purging should be enough!
Well, you don’t find Pearls in every one!
The hint of diesel on the tip of the tongue was distinctive.
Let’s just stick to the burgers on the BBQ
The canal is dirty slow flowing.
My AP water would be like heaven.
Is there a danger of importing parasites?
How do you put a piece of grit in a mussel to encourage it to make a pearl?
Several days of warmer weather have brought a few challenges.
The temperature in the shed was 20*C yesterday evening and I was a bit surprised to find the air pump had cut out. Switched it off. When touched it was hot. I let it cool for a few hours and it restarted OK. A thermal cut out. To operate at around 20*C seems a bit on the low side to me. I will have to monitor it.
The inside Ft touched 17*C and the Trout are off their food. Carp and Perch on the other hand very happy. As you can see from the not very good photo.
Although the main pump runs 15/45 I tweak it a bit. It is now set to run a bit longer in the night. When it is cooler. Less in the heat of the day.
All the plants seem to be doing well. Some of the cucumber leaves are a bit yellow So I have increased the amount of liquid sea weed fertilizer I am adding. That accounts for the brownish tinge to the water.
Thunder storms forecast. I wonder if fish react to them?
It is two weeks since I added 15 Mirror Carp to the main Fish tank. They immediately disappeared into the darkest corner. I let them be for a couple of days and then started feeding. Very small quantities of small floating pellets. The pellets seemed to disappear but I could not observe them eating. I wasn’t sure wether the food was simply sinking and disintegrating. So I did a test. A few pellets in a glass of water. Three hours later they had swollen a bit but were still floating. So now I knew they were being eaten. The fish were by now venturing out a bit but very much keeping to the bottom of the tank. Still not able to watch them eating.
Yesterday I dropped some sinking Trout pellets into the front corner. Soon the whole shoal were having dinner! Two more table spoons before they were full.
On the side of my tank there is a small amount of brown bio-slime. This morning I watched one carp grazing on this. A balanced diet! Protein and veg!
Water measurements are all good. Ammonia just a trace; Nitrites zero. Ph is about 7.2 The Nitrates are on the low side but I have some heavy feeding Brassicas etc and now the Carp are feeding well I expect a slight rise. The warm weather over the last few days has raised the water temperatures. Averaging about 15*C with a morning overnight low of 13 and an evening high of about 17.
I finally seem to have controlled the slug/snail problem. Still finding a few on my late night sweeps but none in the, “red” zone.
The purple sprouting broccoli is starting to develop the characteristic florets and the cabbages are bunching up to form heads.
I stuck a few cutting from existing rosemary and lavender plants into rock wool cubes.These are in the DWC time will tell if they root.