Setting up an 'Autopot' system - 19/02/08

This hydroponic system is one of my favorite systems to use in the greenhouse because its so easy to set up and takes very little care and attention to maintain it. 'Autopot's' come in 2 variations, the 1 pot system (pictured left) and the 2 pot system (i will set up later this month). The 1 pot can be set up to one small reservoir or you can link up multiple pots to one larger reservoir as i will be doing here. The one pot module consists of a square 15l pot, base tray and lid, one 'aqua valve', 1.5m 4mm flexible tubing and 2 root control mats.

The autopot is a simple yet clever method hydroponic growing. The 'aquavalve' lets nutrient solution fill the base of the pot to a depth of 20mm, once it has filled to 20mm the valve shuts off. The plant will then use the solution in the base of the tray until there is none left, once all the solution is used the valve refills the tray to 20mm again. The is all done without the use of electricity and you dont need any pumps. This system is described as 'plant driven' as the plants uptake drives the irrigation.

The autopot comes with very clear instructions that are easy to follow. One very important factor in setting up is making sure the aquavalve is set properly. The picture shows 2 valves, the one on the right is set correctly while the one on the left is not. You can tell by the the way the float is sitting lower on the left valve than the right. To set the valve simply pull back the top float and remove the yellow rubber, clean it and push it back in firmly. Job done.


Once the valves are set attach the 4mm tubing to in and fit the valve in the base tray by allowing the raised tee on the base to sit in the half moon recess on the valve. This will allow the valve to sit securely in the tray. I'm connecting 4 Autopots to one 1ooL reservoir although this size reservoir could feed up to 10 pots without a problem. The reason i use a large reservoir is so i can leave if for long periods without having to keep topping it up. To connect to 4 Autopots to the tank i use 3m of 13mm flexible pipe, a 'Hoselock' tap connector, two 13mm>4mm 'X connectors' and one 13mm flow control tap. In the picture you can see the Hoselock connector attaches to the tap on the reservoir which is attached to the 13mm pipe. The 13mm pipe runs between the pots with the 'X connectors' in position to connect the 4mm tubing from the aquavalves to the 13mm pipe. At the end of the pipe i fit a flow control tap and keep it closed, i will occasionally open this tap at allow and residue build up in the pipe to be flushed out. Notice the reservoir is raised on a stand to use gravity to increase the pressure to the valves.

Now the pots are connected i place the root control mats in , the copper one goes in the tray copper side up and the black one goes in the pot. On top of the black mat in the pot I put a layer of clay pebbles about 3cm deep. This will stop the very base of the pot from getting waterlogged. On top of the clay pebbles i use a mix of coco coir and perlite (20% perlite to 80% coco coir). I am growing a variety of chilli in the autopots called Joe's Long. These have been propagated in rockwool blocks. On planting I bury the bottom third of the block in the coco/perlite mix as shown in the picture.



To finish it off i fill the top of the pot with clay pebbles and cover the rockwool block with a block cover. These pebbles on the top of the pot will help to insulate the pot and will stop the top layer of coco/perlite mix getting dried out by evaporation from the sun or grow lights. Once the plants are in i hand water them from the top with Canna's coco A+B at an EC of 1.6 and a pH of 5.8. These plants will get hand fed from the top for the next 2-3 weeks until i'm sure the roots have made their way throughout the entire pot and the plant is ready to be fed through the valve at the bottom. If you start by feeding from the bottom straight away quite often the plants small root system cannot cope with the saturated growing medium and will get off to a slow start. By hand watering every 2-4 days for a few weeks you will get the plant ready quickly for bottom feeding. I have filled the tank with nutrient solution but have kept the tap on the bottom of the reservoir closed, this way i can top feed the plants with a jug out the reservoir when they need it.

Cant wait till I've got some lovely long hot chillies in a about 3 months time. I find chillies and peppers the best plants to grow in Autopots, although I've had good success with melons, and tomatoes too.

Setting up a 'Wilma' for Hydroponic Cabbage- 15/02/08

This hydroponic system is a low pressure recirculating drip system and is named the 'Wilma'. This is made my Nutriculture and comes in 5 sizes from 4 pots to 20 pots. This one is the most popular amongst growers, the Wilma 8 pots system. This system has a reservoir as the base on which the tray is placed to support the 8 pots. A submersible pump (maxijet 1000) sits in the reservoir which is attached to a supply pipe with one dripper branching off to each pot. The nutrient solution is pumped from the reservoir, through the drippers and through growing medium in the pot finally returning back to the reservoir. I have previously used this recirculating drip system to grow herbs, potatoes, tomatoes and chillies but this time I'm using if for a variety of cabbage called 'Green Chancellor'.

This system is extremely easy to set up, all you do is place the tray on the reservoir, position the square pots in place and connect the drippers to the supply line, this only takes few minutes. With the Wilma system you have a choice of growing mediums, i am going to use coco coir and perlite mixed at 80% coco to 20% perlite.




The square pots for the 8 pots system hold 11L of growing medium. I place 2 strips of spreader mat in the bottom of the pot to cover the large holes to stop the growing media from falling into the tank while still allowing water to flow freely. I then add around an inch of clay pebbles in the bottom to help get good drainage and top up the rest of the pot with my mix of coco and perlite.



As with every hydroponic system i always ensure the my plants are very well established before transplanting them. You can see the roots of this cabbage plant are abundant and healthy. After the plants are potted into their larger pots i water them in by hand using Canna's Coco 2 part A+B nutrient at an EC of 1.6 with a pH of 5.8, i also add Vita-Link 'Bio-Plus' which is a fantastic rooting stimulator. Coco coir and perlite are both inert growing mediums so need to be watered with nutrient solution straight away.

Now they are watered in i will water again in 3 or 4 days by hand. I always water enough so a little run-off leaves the pot into the tank. I'll hand water the plants for 2-3 weeks until they need to be watered everyday at which point I'll fill up the reservoir beneath and used the pump to irrigate the plants once a day using a timer. Too much water straight after transplanting can get them off t a poor start so i make sure they are well established in their pots before feeding everyday. This variety of cabbage can get quite big, only time will tell.

Transplanting part 3 - 18/01/08

I plan to grow my cabbage plants this year in a hydroponic drip systems know as the 'wilma'. The plants will be grown in a mix of coco coir (80%) and perlite (20%) so I prepare enough of the growing media to fill 10 small square pots.

Once the pots are filled the seedlings are planted in and water through with a coco coir specific nutrient solution (I use vita link coir or canna coco) at an EC of 1.2. I always water until there is solution running out the bottom of the pot to ensure all the media is sufficiently damp. The perlite helps increase the air spaces in the mix stopping the coco staying too wet, creates better drainage and helps stop compaction.

Now I've got all the seedlings planted up into larger blocks or pots they are arranged on the air pruning tray and the light is lowered to get an even distribution of light to all the plants.



To keep the relative humidity between 65-75% I have a humidification system controlled by a humidistat. Before i used these devices the relative humidity would be around 30-40% plant health was quite poor. The white Humidifier in the picture is a centrifugal HR-50 and the mist coming out the black tank is produced by 2 ultrasonic 5-disk mist makers. The mist produced by both devices is cool and in summer helps to lower temperatures too.