Project Diary

It’s a gentle day at the project. I like it when Sam and I get to work together, we are both… doers – makers – and today is one of those days. Sam picks me up on his way to the warehouse, and we head to Greens Horticulture for some advice on winch systems for our lighting rigs. We are in luck – as we often are when we visit Green’s. Matt has just the thing, and we can have it for free because it’s from an old display and all the winch strings are tied in knots! We buy coir for propagating some watercress for the big-rig – we can see that it will be ready soon and we will need some baby plants, and Matt recommends some organic nutrient to give the baby plants a little boost once their seeds initial nutrient has been consumed. We swing by the supermarket and I buy big bags of chopped vegetables for meals for our volunteer workdays. We eat together after working on the project on Thursday nights and Sundays and I want to make sure there is something fast and healthy we can share.

Today we decide to work more on the IBC scale eel system as it is here that we will be receiving our eels in February.WhatsApp Image 2018-01-23 at 22.57.34

Last Friday, whilst I was in London visiting Paul Bavister at Flanagan Lawrence to talk about our modular concept system, Sam and Tom worked on further testing u-siphons as an option for draining the flood & drain system. Today we get it to fire as a working system. Then we build a sort of rigging for our lighting system.

WhatsApp Image 2018-01-23 at 22.57.26

It’s a good size as it is roughly speaking half the length of 1 of our big-rig bays. Which means we can test out the efficacy of our lighting array (spacing, height etc).

The rest of the week is looking exciting.

Thursday Jon the electrician is coming to help us set up lighting in our classroom. Plus Alan from Big Issue Invest is coming over to talk to us about our bridging loan request. Fingers crossed they can support us in this endeavour!

Friday Tom and Sam and I will complete the IBC build and get that cycling. Plus there is a lot of admin to do. I plan to apply for funding to pilot the module and I need to begin making preparations for our eel project launch on March 12th!

Sunday we are having a workday (if you fancy helping out you can sign-up here). The main job will be to start setting up our propagation area for the big-rig and to clear some of the drains that are full of autumn leaves in the Garden.




Interview on Ujima Radio

If you didn’t catch us yesterday, we were interviewed by John Kennington aka JK for the Babber’s show on UJIMA 98FM Radio as part of a food, health and community special. Was lovely to be joined by Katy of Street Goat – a local project in Bristol that we just love here at the fish project. Its all about using marginal land to build community through food! The Babber’s show is aimed at an older listenership and encourages listeners to get involved with the projects in the show. We are in the second hour but the first hour was also really very interesting with great interjections from a local Dr who talks about how our projects can contribute to a healthy city!

Bristol Fish Project has a new warehouse home!

Wow it has taken such an epic time to finalise, but today it is DONE we have signed and ratified a lease for an 18x10m Warehouse with some gardens and hard standing here in beautiful Bristol!


The unit has some fire damage and isn’t yet a biosecure environment, so a hardcore programme of renovations should carry us into January, with production set to start in March 🙂

We are going to need all hands on deck so if you can help us with the renovations – particularly if you happen to have some super useful skills please let us know!



Fish Harvesting


Yey the fish harvest has started! I have taken 6 (10% of total of 61) Tilapia from the tank & they averaged 200g each! Although they are plate sized my research tells me an average fish size should be 450g. There are some bigger ones in the tank they were just to fast to catch, there are also lots of smaller ones as well. I needed to have less fish in the tank because the nitrite/nitrate levels were getting to high to regularly. So I have frozen them & will collect more until I have enough to feed everybody who volunteered there time & energy making the Bristol Fish Project happen. I have a field kitchen & am willing to pull up in a green space in Bristol & cook up a picnic for all those who wish to chow down on this amazingly hardy fish (I wonder what they taste like?) Tilapia were the most farmed fish in 2012 so I find it strange that no one in the UK has heard of them. Anyways anybody is welcome to come & see the setup in the shop! Contact me first to make sure I am in.

Fish Feeding

Just a little video so you can see the fish, Having a problem with the small bell syphon I have added in the new flood & drain system. It keeps not working. Seems you have to have just the right amount of water coming into the growing bed? To little & the syphon wont kick in! To much & it wont stop! I’m thinking that the delivery tubes to the NFT will have to be changed as they are rather small & could be blocked up quite easily! As for the fish they are starting to grow recognisably into Tilapia with the head almost dropping down to the front of their bodies.

Wow what a fiddly job this set up turned out to be. The new Aquaponic set up using NFT & Flood & Drain in Chippenham in the UK. If you want to come & see it at Bill & Bens HydroWorld you will be most welcome. Check out the link to see a video!

A dripping, post-apocalyptic, Aldous Huxley nightmare…

This winter, albeit mild has been a hard one for the fish project! Here we talk about our main challenges chosen solutions and share photos:

IMG_1769In November, the tanks which we had maintained at 24 degrees during the dropping temperatures of late October were no longer holding that temperature over night and gradually in one of our tanks (which runs on overflow from another) we were seeing a drop towards 22… and then at its worst 19 degrees. The tilapia in that tank were sluggish and not feeding well and we could see that their immuno-response was reduced as every few days one would be lost to streptococcus – a naturally occurring bacteria that overwhelms fish when they are weak and causes haemorrhaging in the anus as shown in the photo. We decided to add more water to the polytunnel to increase thermal mass, in the hope that the heat we did add to the system wouldn’t be lost too rapidly. Then we further insulated the tanks with a rockwool layer fixed with pallet wrap, added mini polytunnels over the tanks, and we bubble wrapped the polytunnel – it worked – adding a few degrees to the tank temperatures, but was ugly and dripping – a post apocalyptic, Aldous Huxley nightmare… Continue reading

The balancing act – nutrients and pH

Signs of Iron Deficiency in the Mizuna

We’ve started to notice our plants getting lighter green and veins appearing on the leaves – we’ve got a nutrient deficiency on our hands… Working with an aquaponic system – particularly a young system, is a balancing act. The fish produce waste, bacteria break this down and then plants absorb the nitrates, and macro /micro nutrients. The ease at which nutrients can be absorbed by the plants is affected by the pH of the water. In our system the pH has been a little bit high for the nutrients to be in a form the plants can readily absorb. Bristol has very hard water – pH 7.4 in our tanks.  We’re using peat pellets to try to slightly acidify the system. Seems to be working – pH readings today were down to pH7.2 today.

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Figuring out when ammonium levels are too high…

I had a minor freakout at the polytunnel today when on testing the ammonium levels were at 3mg/l. So why are the fish not even the teenyest bit dead? Here they all are – not one lost by the way since aquiring them… yet even the test kit says YOUR FISH ARE ALL DEAD NOW alongside the dubious looking green marker that matches the colour that has emerged in my test tube. I immediately changed up 200l of water (thats what I had de-chloraminated to hand) and got a reading of 1.5mg/l. That was a slight improvement, but should still be enough to do away with my fish within a few days… That is depending on just how much of this reading pertains to toxic un-ionised ammonium (UIA), and how much is of the approximately 100 times less toxic ionised ammonium…

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Fly World the new “mile-high club” for Black Soldier Flies

James came in last week, to hammer, stretch and stick together a flying net for ‘fly world’ –  a cosy home for our resident black soldier fly larvae. Black soldier flies mate in flight – the net cage you can see in the picture that James is so proudly showing us is in effect the ‘mile high’ club for our flies.

We’re setting the system up so that the larvae self-harvest when they are ready to turn into flies. They crawl out of the biodigestion unit where we put the waste food, and drop into another unit – there we will be deciding which ones to let develop into flies, and which to use in the fish feed.

At home the larvae are eating their way through spent grain from a local Brewery, and other food waste that we can chuck in. No sign of any flies yet – though we’ve only just started incubating the mix to a balmy 30 degrees. Hopefully the return to the polytunnel which in this shabby weather is rather less cosy won’t slow them down too much!

Hotting up in the polytunnel

We are now monitoring the water temperature in the first of our 2 700L – ish tanks. Today’s max water temp was around 30 degrees, with around 49 degrees max recorded inside the polytunnel! – Will be interesting to see how low or high the water temperature will get in the next few days.

We are working on reducing the temperature ‘swings’ by increasing thermal mass in the polytunnel, if we get our desired 8 tanks, we should be getting towards a much stable environment for our plants and fish!

The next problem is shading – how to keep the plants from bolting or shriveling up under the hot hot sun! Watch this space for our attempts at stabilising our little ecosystem!

The Lab!

We have… A LAB… huge thanks to Bridget, Aedon, Matt and Sam for the mega work yesterday!!! Now we can start lol!!! Got a bit much sun, but its fantastic to see the polytunnel up and ready to roll! It is absolutely scorching in there when the sun is out!!!