The winter months are typically as a slightly quieter time, and this year has certainly been no exception - especially with Covid 19 and lockdown, which has closed a number of our markets. However it is our one opportunity to grab some time to do other things. For example Sal has been writing her Seychelles' book - hence the much reduced blog activity, whilst Melv has been trying new growing methods and looking for ways in which we can improve what we do.
Driven by the need for consistency, and to try to make our growing a little more fail safe, Melv has taken us a step closer to our aspiration to grow aquaponically. He has been beavering away on setting up a very impressive hydroponics system, which is basically aquaponics without the fish. Not having fish, may suggest that it is the simpler of the two processes, but it could in fact even be argued that it is more complicated, due to the system needing to be fed.
The main difference to growing conventionally is that the crops are grown in LECA, (lightweight expanded clay aggregate) rather than a compost based material. LECA is an inert gravel, which basically hosts the roots of the plant.
As an inert material it provides consistency, but obviously does not contain any nutrients for growing - these are added, via a watering system - hence the name hydroponics. The existing flow beds were the perfect hosts for Melv to try and experiment with this new system hydro system.
The plants are sown in trays like conventional systems, but instead of being filled with compost they are filled with LECA, like the pak choi above and the salad below.
To provide the nutrients needed the system works on a flood and drain approach, which is achieved through automatic pumps set in a sump.
Our sump, located underneath the flow bed, is a lined wooden box, which is filled with nutrient enriched water and houses the pump. The pump takes the water from the sump into the flow bed, once the water reaches the required level, to just short off the top of the growing trays, it then drains through a pipe back down into the sump, (shown below) allowing it to be recirculated.
Sowing into LECA is far simpler than using compost for a number of reasons, but in main it is clean, which means that there is no need for the trays to be cleaned after use like below, which for Melv is a very wet and cold activity - not great at this time of year!!
and also the seeds don't need to be covered, they can simply sit on top of the gravel, like the peas and salad below
which not only saves compost, but also quite a bit of time.
We are currently growing salads, pea shoots and pak choi hydroponically and Melv has researched the nutrient needs of each - and this he regulates by frequent monitoring and adding what feed is needed. In an aquaponics system this is not needed as it is provided by the dirty water created by the fish and so it taken care of.
Melv looks at the pH and the conductivity, which measures the amount of salts in the water. The results have been fantastic and all three types of produce are comparable if not better than growing through conventional means.
The pak choi - which has been very popular with local Godney residents
The salads - which are in great demand as ever, by the public and businesses alike
and the pea shoots are doing extremely well and seem to grow as you watch them...
As the produce grow the flow beds look amazing, a sea of green stretching through the polytunnel
The system has been an incredible success and has already transformed what we do, with the potential to make a large part of our growing operation not just more consistent and more sustainable but far more efficient.
Building on this success Melv is now working on converting the salad tunnel
And through a clever system of pipes and guttering, he has already got half of it up and running - amazing
In the same way a pump takes nutrient enriched water from a sump and circulates into the trays to flood the LECA and provide the seeds with what they need.
It is progress which is extremely exciting on many fronts and the start of our future approach to growing. We now look forward to having the added bonus of taking this to the next step of a full aquaponics system and of course then having fresh fish to eat!!
