Setting up an IWS Flood and Drain system - 20/02/08

This 'Flood and Drain' system is very popular with hydroponic growers who like the flexibility of growing in pots with the added benefit of an automated irrigation system that recirculates the nutrient solution. The system is made up of 4 main components, the reservoir, the 'brain', the timer and the pots. The system works by periodically filling and draining the pots from the bottom with nutrient solution. It does this by switching on a pump in the reservoir that fills the brain unit. All the pots are conntected to the brain so as the brain fills so do all the pots. When the brain is full a float switch is activated which turns off the pump. Once all the pots have been flooded a pump in the brain is activated which drains all the pots by pumping the solution back into the reservoir. The IWS (Inteligent Watering System) is made by Direct Garden Supplies in Sheffield, UK. This pot based flood and drain system has been around for many years and was originally brought to the UK market by 'Highlight Horticulture' in Nottingham which they call the 'Multiflow' System.

The IWS system is very easy to set up. First thing i do is set place the pots in position. The pots are made up of 3 parts, the stand, the outer pot and inner pot. The stand has small inbuilt slope that allows the pot to fully drain. The inner pot has loads of holes the the bottom, this is placed inside the outer pot.

Once the pots are put together the sealing gland needs to be attached. This has 2 parts, the nut and rubber sealing gland. The gland on the outside of the pot needs to be very tightly screwed to the nut on the inside of the pot. Once the gland is in the connection tee or elbow needs to be inserted through the gland and tightened. This will form a water tight seal through which the pot will fill and drain. The same glands needs to fitted onto the brain and straight connectors need to be fitted. This will enable the brain to be connected to the pots with flexible 16mm pipe.

When connecting the brain to the pots i always heat the pipe in hot water before pushing onto the barbed connection pieces. Also, i always lay some extra pipe between the pot and the brain which i loop betwwen the pots as shown in the picture. I do this for a reason, when the plants are small i group the plants close together and as they get bigger i pull them further away from each other. The extra pipe work allows me to do this. If i knew the plants were staying in the same position i would cut exact lenghts to join the pots to the brain. After all the pots are connected i attach the timer to the brain and mount the timer on the wall in an easily acessible place.

Now the system is ready i get the clay pebbles ready for planting into. The pebbles im using have already been used last year so i have soaked them for 24 hours in a water with hydrogen peroxide(aka Oxy Plus) added at 50ml per L. Although i didnt have any problems last year the peroxide should kill any nasties that may be lurking around. After the soak i lift them out using the inner pot and then rinse them thoroughly with tap water.

Once the clay pebbels are thoroghly rinsed i fill the pots three quarters full. Then i fill the 220L reservoir with water and add 22ml of Vita-Link Bio-plus and Vita-Link Max Grow A+B nutrient to a EC of 1.5, i then set the pH to 5.8. Now the nutrient solution is ready i turn on the timer and start a flood cycle. As the soultion slowly fills the pots the clay pebbels will take in the pH balanced nutrient soultion and the beneficial bacteria (from the Bio-Plus) preparing them to be planted into. If you only wash them with tap water and plant straight in the pH will be too high in the pebbles which could cause some inital nutrient uptake problems.

I want the maximum flood height to be the same level as the clay pebbles so i watch the pots filling untill i can see the water level raising to the surface. As this happens i push down on the pebbles with the palm of my hand to make sure the pebbles arn't floating. As the water rises i keep adding pebbels utill the water level is the same height as the pebbels. When the the brain stops filling and all the pots have the right amount of clay pebbles and solution in, i leave them soaking in the nutrient solution for 1 hour.


After the 1 hour soak i initiate the drain cycle on the timer. Once the drain cycle is finished i get my stop watch ready on my phone. I start another fill cycle and start my stopwatch to time how long it takes for the pots to fill back to the max flood height. It took 4 mins to reach the desired height and i want the flood height to remain steady for 1 min. This allows the rockwool block to draw up nutrient solution by capilary action. This means i should set the timer to 5 mins. Now i know the desired flood duration i plant the blocks into the pots by placing them 1 pebble deep in the pebbles so the flood height will reach the bottom quater of the block as shown in the picture.

Once they are planted in i fill the top of the pot with pebbles and set the timer to 1 flood a day for a 5 miute flood duation.Once the plants are settled in I'll support them with strings. Hopefully all will go well.

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.

Hydroponic Pineapple- 17/02/08

I have been growing this pineapple plant for nearly 2 years and in November it finally started to produce a fruit. it has taken another 4 months for it to extend out from the center and mature on its stem. Its has been quite an effort to get it to this stage because its so difficult to tend to as the spikes on the edges of the leaves rip my hands to shreds. It is growing in a small 'Flo-Gro' system which it has now outgrown. It was in the greenhouse for over a year but i moved it into the corner of the upstairs shop area has i couldn't stand getting scratched all the time.


This particular variety of pineapple is not edible and mainly grown for ornamental purposes. Some people use the small colourful fruits in flower arrangements. I think I'll try to grow an edible type next and try to find a type that doesn't have such spiky leaves. Pineapples are fairly easy to propagate from the leaf set on top of the fruit so next time you buy a pineapple give it a go!

NFT Cucumber Progress 16/02/08

In 11 days these cucumbers on the NFT Gro-Tank have more than doubled in height. They are well established onto the system are i have emptied the reservoir and replaced the nutrient solution with an increase in strength up to and EC 1.8. I think I'll be picking my first cucumber in about 25-30 days!







This picture of the roots shows how well they are extending from the rockwool block. Soon there will be a thick mat of roots all over the tray.

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.

Setting up a Hydroponic NFT Multi Duct- 15/02/08

This Hydroponic system is a large NFT 'table' made by Nutriculture and is know as the 601 Multi Duct. These systems come in various sizes and configurations, this 601 is about 2m x 1m with a 125L reservoir. With this system a submersible pump (maxijet 500) is positioned in the tank at the drainage end and pumps nutrient solution up the middle of the tray through 1/2" supply tube where it splits at the top through a tee piece into 4 outlet fittings (2 x tee's and 2 x elbows) where the solution enters the top of the tray. From here the solution flows down the tray and drains back into the tank. The tray is supported by a stand at the top end and the tank at the drainage end giving the table a slope of 1 in 50. This type of recirculating hydroponic system is great for growing all types of plants, I'll be using it this year to grow my favorite mini plum tomato called 'Floridity'.


After setting the system up and fitting all the pipe work i run through a solution of Hydrogen peroxide at a dilution rate of 50ml per 10L for about 4 hours. This will sterilise system killing any bad bacteria that may be lingering from last year. Once the system is clean i lay down the spreader mat which helps to keep the flow of nutrient solution even down the table.






Now i fill the tank with water and add Vita-Link 'Easy Grow' at a EC of 2.0 and pH of 5.8. Once the tank is well mixed i turn the irrigation pump on. The Nutrient solution will flow quite rapidly if you have the pump on full so it has to be adjusted down using an inline flow control tap which i position near the pump in the tank. I turn the tap to adjust the flow rate so the solution lands in the first channel as shown in the picture. Once the flow rate is set i leave the pump running 24/7.


Now the system is running i get it ready to be planted into. Using a black corriboard i cut holes out where i want my plants to be. Notice i stager the planting to allow good water flow down the table. Once the holes are cut i cover the whole table and tank with black and white sheeting (white side facing up) to help insulate by reflecting and light away from the root zone and tank. I cut an X on each hole to allow the plants to be planted through the black and white.





On planting i have tied the roller hook string around the 4" blocks like i have when i set up the 604 gro-tank with the cucumbers and hung the hook from the roof supports. This will allow me to train the vine up the string for support. Now the plants are in and the nutrient solution is flowing all i do now is monitor the solution in the tank every few days to keep the pH and EC in range. As the nutrient solution is recycled i expect to completely change the solution every 7-14 days. Cant wait for my first harvest which i expect will be in 8-10 weeks!

Rockwool Drip System - 12/02/02

The tomato plants are now firmly rooted in, a light twist of the 4" block shows they strongly held to the slab. I have removed the canes and strung the vines up with the roller hooks. Now the plants are ready the drippers are inserted into the block and i set the digital timer for the irrigation pump to come on for 3 minutes every 2 hours while the lights are on or sun is up. I set the first irrigation to come on 2 hours after the lights come on and the last 2 hours before the lights go off. On these first and last irrigations they get 6 mins.

The nutrient solution being given to the plants now is Vita-Link 'Easy Grow' at an EC of 2.5 and pH of 5.8. The general rule of thumb for drip systems is 'transpiration before irrigation' so i start the irrigations 2 hours after the lights come on knowing at this point the plants are taking up nutrient solution for the slab. I make sure on each irrigation that some solution drips out the slab, this run off wants to be around 20-40% of the input volume so if you give a slab 1ltr you want to see around 200-400ml of run off. The easiest way to check you getting enough run-off is by time, if your irrigation length is 3 mins then you want to see the slab getting run off after about 2 mins after the pump comes on. The picture shows the high pressure filter set in the nutrient reservoir, i keep the overflow valve open slightly so on each irrigation the soultion will mix and aerate.

I have covered the run-off tank with some black plastic corriboard to prevent algae growing in the open water. All i have to do now is make sure the reservoir is topped up with nutrient solution and empty the run-off tank once a week.