Vid #6 Conference clips – Plants, Organics, Jade Perch, Barramundi.

A morning with Murray at the Aquaponics Association Conference in Orlando September 2011.
This  clip  discusses
Plants, organics, aquaponically grown, jade perch, barramundi.

Vid #7 Conference Clips – Shade Sunlight, People Power, Filters.

A morning with Murray at the Aquaponics Association Conference in Orlando September 2011.
This 7 (approx) minute clip  discusses
Shade and sunlight, people power, fish food, duckweed, NFT, filters.

Vid #8 Conference Clips – More Water Means More Stability.

A morning with Murray at the Aquaponics Association Conference in Orlando September 2011.
This 10 minute clip discusses
Clay pebbles, Grow bed depth, Floating raft connections, Nutrient in raft beds.

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Continuous Flow Systems.

Continuous flow systems deliver the water to the grow bed continuously and the water is most often distributed over the grow bed by some sort of distribution grid. (see photo below) This consists of pipe work with small holes drilled at regular intervals to facilitate the even distribution of nutrient rich water.

The water trickles down through the grow media and out of the bottom of the bed. The grid distribution system is important to ensure that all parts of the bed receive water. If a grid irrigation system is not employed, dry areas develop in the bed resulting in poor and / or irregular plant growth.

Continuous flow is very easy to set up and operate from a plumbing point to view, but it does not deliver optimum plant growth in a media based grow bed system.

Choice of media is important. Clay pebbles are a good medium for this type of system as they retain moisture thereby aiding the growth of the plants. Clay pebbles have a slight "wicking" effect helping to distribute water to the entire bed.

Another way to overcome the difficulty of poor water distribution is to have the outlet up from the bottom of the grow bed. A short up stand, will provide a reservoir of water in the bottom of the grow bed. This means that the bed will be “flooded” permanently to the depth of the up stand. This would typically be 50mm or 2” deep.

The roots of the plants get down to that level as the plant matures and draw water as required, and if clay pebbles are employed as the grow media, the water can "wick" up to the remainder of the bed. This reservoir of water can become stagnant and anaerobic if the flow of water into the grow bed is not adequate.
Continuous flow is also employed in “Floating Raft” systems, and NFT systems. These two methods are not usually employed in home systems. Of late, we are delivering more systems with a Floating Raft component built in. There is just no better way to grow lettuce !

Typical small scale NFT table Murray Hallam Practical Aquaponics

Typical small scale NFT table.

N.F.T. or Nutrient Film Technique, is widely used Commercially in the Hydroponics industry.
A thin film or trickle of nutrient rich water flows down the PVC channels. Holes are provided in the channels in which the plants are grown.  The roots of the plants draw up moisture and nutrient from the passing water. This system is well proven and is excellent for growing salad greens such as lettuce.
The water is collected at the end of the channels and returned to the fish tank.
It is necessary to pre filter the nutrient rich water to remove any solids before the water is passed down the channels. Reduced growth is experienced if solids are present in the water as the solids will adhere to the plant roots and reduce oxygen uptake by the roots.  NFT is easy to set up and relatively low cost. Disadvantages are instability in root zone temperature and lower overall water volume.

Lettuce growing in a floating raft bed. Murray Hallam Practical Aquaponics

Lettuce growing in a floating raft bed.

Floating Raft. or D.W.C.
Floating Raft or Deep Water Culture is another way in which continuous flow is employed.
This is the most common method used in Commercial Aquaponics.  Water is pumped from the fish tank via a filter system to remove any solids, to the grow troughs. The plants are grown in holes drilled in "Floating Rafts". The roots of the plants are submersed in the nutrient rich water.
The advantages of this system are the ease of harvesting, and the greater volume of water employed in the overall system. Greater volume of water means much better stability for the entire system in both temperature and pH. There is also a more stable and consistent delivery of nutrient to the plants.

Continuous Flow water distribution grid in a typical grow bed..  Murray Hallam Practical Aquaponics

Continuous Flow water distribution grid in a typical grow bed..

In Summary,
Continuous flow media based systems are simple to set up and operate, therefore that are usually the least expensive for hardware requirements.
Uneven watering and dead spots can occur in the media based (gravel or clay pebbles) grow bed.


Bath Tub Kit Assembly Instructions.

The BATHTUB Aquaponics Kit assembly instructions are for the home builder to make a working Aquaponics Kit from 2 x recycled bath tubs.
The instructions contain, a list of pipe and parts, pump specification and how to make an auto siphon.

Aquaponics system made from recycled bathtubs.

Aquaponics system made from recycled bathtubs.

You can download this file to your computer and print it on your printer for your own use.  The file is strictly for your use only.  Distribution to friends or to anyone by any means is a breach of copyright.

Download the instruction file.
Click HERE 


You can purchase a complete parts, pipe and pump kit if that suits you better.  Just find two old bathtubs and follow the instructions .  See HERE. (Link coming soon)








TotePonics CHOP2 Kit Assembly Instructions

The TotePonics CHOP 2 Aquaponics Kit assembly instructions are for the home builder to make a working Aquaponics Kit from 3 x IBC or Tote containers.
The instructions contain cutting instructions, a complete list of pipe and parts, pump specification.  There are 20 pages of instructions, diagrams and photos.

You can download this file to your computer and print it on your printer for your own use.  The file is strictly for your use only.  Distribution to friends or to anyone by any means is a breach of copyright.

Download the file here.

Aquaponics Insurance Plan. What will you do if disaster strikes!

Imagine having your home grown crop of Trout , Barramundi or Tilapia almost ready for harvest. You are already planning the family get-together when you will proudly serve that wonderful fish dinner.
Then, while you are at work there is a three hour power outage…the pumps stop…the aerator stops…and disaster….all your fish are dead.

The most important piece of equipment in your Aquaponics setup is your back-up aeration system. It is important like backing up your computer files on your PC or Mac. A backup routine or system doesn’t matter and seems unimportant until you have that first disaster…loosing those important documents or assignment on your laptop, or loosing all those ready-to-harvest fish.
After that kind of event backing up becomes a normal part of your everyday routine.

Fish need oxygen just like we do, and it will be very quickly used up if the pump and aerator are not operating. Without aeration taking place, in as little as 30 minutes fish can begin to suffer gill damage and not many minutes after that …death.
Most fish deaths that occur in Aquaponics systems because of nil or too little dissolved oxygen in the water. That is another discussion for another day, but the importance of an excellent aeration system cannot be overstated.

So, what kind of things can we do in our Aquaponics fish tank to make sure that the water is aerated.

There are several commonly employed techniques. No doubt there are countless variations to these methods, but listed here are the three main and most useful means of keeping the dissolved oxygen levels up.

UPS is short for Uninterrupted Power Supply. UPS units are commonly used in the computer industry. These devices are obtainable from computer outlets and vary in cost depending on the sophistication of their design and the electrical load they are intended to supply.

UPS..Uninterrupted Power Supply - Typical unit. Murray Hallam Aquaponics

UPS..Uninterrupted Power Supply - Typical unit.

They work like this. The UPS is hooked up between the mains power supply and your pump and aerator. Mains power is funneled through the UPS to supply to your pump and aerator. The UPS will attempt to supply consistent power to your appliances by topping up any voltage shortfall from its inbuilt battery. The DC electricity stored in the inbuilt battery, and drawn from the inbuilt battery, is converted to mains type electricity by an inbuilt “Inverter”

So, if the mains power goes down, or completely fails, the UPS will keep your mains power devices operating normally for a short period of time. Most UPS’s have an audible alarm to alert you to the fact that the mains power has diminished or dropped out altogether. This is a useful feature although it is of little value if you are at work or not within earshot.

The business end of a UPS. There are several mains power outlets. Murray Hallam Practical Aquaponics

The business end of a UPS. There are several mains power outlets.


The main disadvantage with using a UPS is that it will only keep a pump running for fifteen or twenty minutes at best. It will keep an aerator running for an hour or two because aerators as used in domestic systems typically draw less than 20 watts.
This time can be extended by purchasing a very large capacity UPS, or by having larger batteries wired into the circuit of the UPS. This can become a very expensive exercise.

Once you have the UPS unit hooked up, leave connected long enough to make sure the internal battery is fully charged then pull the plug out of the wall and see just how long the UPS will keep your equipment running.

Auto Switching AC/DC Air Pump.

There are a variety of these available through aquarium shops and on-line. They operate normally on mains power and have built into them a place where normal dry cell batteries such as torch batteries can be fitted. More sophisticated models have a larger rechargeable battery.
As the name suggests, when the mains power goes off the unit will automatically switch to battery and continue to run supplying air bubbles to the fish tank. These devices have been designed specifically for the aquarium industry and are just wonderful for home aquarium tanks. They generally do not deliver enough air for a larger home Aquaponics system unless you are prepared to invest in the largest capacity model available, and possibly, more than one of them.

AC-DC air pump. This unit delivers 9 cfm of air on mains operation and 6 cfm of air on inbuilt battery. It has 2 x air line outlets.

AC-DC air pump. This unit delivers 9 cfm of air on mains operation and 6 cfm of air on inbuilt battery. It has 2 x air line outlets.

You get what you pay for with these devices, the ten dollar model from the on-line auction site is possibly not the wise way to go.
Purchase from a reputable source where you have a really good chance of getting after sales service. Give the device a good work out by running it on battery (switch off the mains power at the wall). You need to know just how long it will run on that battery/s
That is important information, don’t believe what it says on the instruction sheet or box. Do a real test. You need to know how long you have got if there is a mains power outage.

A Fail over Switch and battery backup DC system.

This type of backup system is the most versatile and able to supply aeration to your fish tank for extended periods of time. Because it is based on activating a 12 volt DC pump this system is also able to provide water movement in the fish tank. This is possibly the most efficient way to provide quality aeration over an extended period of time.

Backup Fail Switch Practical Aquaponics

Backup Fail Switch.  This device is available in Australian or USA power configurations.

A complete system consists of a switching device, a battery, a battery charger and a 12 volt DC pump.

When the mains power is interrupted the Fail over Switch senses the loss of power and immediately switches on the battery power driven 12 volt DC pump.
The water being pumped from the bottom of the fish tank and is directed over the water surface. An exchange of oxygen and carbon dioxide takes place by the action of the surface water being disturbed vigorously. Oxygen is absorbed by the water and carbon dioxide is discharged into the atmosphere.
The action of the pump also moves the water around in the fish tank thereby ensuring good mixing of the body of water. The mixing action rapidly distributes newly absorbed oxygen throughout the fish tank.

When the mains power is restored, the 12 volt pump is automatically and instantly turned off. The battery charger is activated and the battery charged back up to full capacity in readiness for the next mains outage.

The battery used is typically a fairly low cost lead acid motor vehicle battery of around 40 AH capacity. This size battery will typically run the back up pump for 6 hours, which is normally sufficient to handle most mains power outages.
If you want more backup time then increase the capacity of the battery/s.

For the possibility of mains power outages beyond the capacity of your battery, it is prudent to purchase a small petrol driven gen set. These days they have become very inexpensive. A small 500 watt petrol driven gen set can be purchased on-line or at tool shops and similar places for around 100 to 150 dollars.

This all may sound like a lot of trouble, having battery backup, and further to that a small generator set, but believe me, you will regret not having it if you suffer a lengthy mains power failure.
Imagine, your fish are almost ready for harvest and you loose them all because there is no adequate back up system.
It is like paying insurance, you hope that you never have to make a claim.

Murray Hallam

Backup equipment. Backup Fail Switches available Here.

Flood and Drain (Ebb & Flow)

Flood and Drain or Ebb and Flow systems.

Flood and drain is the backbone of home Aquaponics systems, and the most commonly employed method of delivering nutrient and water to the vegetables and to filter the water for the fish.
How best to creat the flood and drain cycle is a matter of much discussion.

Domestic or home based Flood and Drain Aquaponics systems consist of ;

1... A fish tank
2... Grow beds
3... Pump/s pipes and other assorted plumbing fittings.
4... Some type of device or method to create the flood and drain cycle.

How best to create the flood and drain cycle.
There are three ways this can be done.

1 - Float switches.
The system is constructed so that a pump in the fish tank pumped the water out to the grow beds until the beds were flooded. The pump was shut off by the use of a float switch in the fish tank.  When the water in the fish tank reached the level where enough water had been delivered to the grow beds, the float switch being tethered in the fish tank in such a manner as to cut the power to the pump at that precise level.

The water in the grow beds drains slowly back to a sump.  Water in the sump is then returned to the fish tank by use of a pump that  is also controlled by a float switch.

In smaller systems or on sloping ground it is possible to arrange the grow beds and fish tank in such a way as to have the water from the grow bed go back to the fish tank by gravity and alleviate the necessity for a second pump, sump and float switch.
As can be imagined in this drawing, the outlet pipe from the grow bed with a little re arranging can be made to flow by gravity directly back into the top or side of the fish tank. The fish tank could also be dug into the ground sufficiently to allow better flow of water back from the grow bed.
.Float switches used in this manner are not reliable long term. They require a lot of re-adjustment and are prone to malfunction.

An animation of this layout can be seen HERE..

2 - Timer.
The use of a timer to regulate the delivery of water to the grow bed is a much better method than the use of a float switch. The float switch is still a useful device installed in the fish tank and set in such a manner as to act as a safety device to prevent the total emptying of the fish tank.

If choosing to use a timer in youe Aquaponics system, a good quality timer is essential.The timer can be set to the exact period needed to deliver the nutrient rich water to the grow beds. The timer then switches the pump off for a period long enough to allow all the water in the grow beds to drain back to the fish tank, and so the cycle repeats.

Example of a good quality timer HERE

This particular timer can be set to the second for an "on" period and to the second for an "off" period. It can also be set to operate only during daylight or dark hours.  This is a very useful function during the colder months when some operators wish to turn their pump off to conserve heat, or if operating on solar power it is useful to turn the system pump off at night to conserve battery power.
The same system of grow bed drainage is utilized as illustrated in the photos above.
If a good quality timer is employed, this method is very reliable and works well.

- Auto Siphons
Auto siphons are an excellent way to create a flood and drain cycle. There is no need for a timer or float switch. The pump can be run continuously delivering water to the grow bed/s. This means that a smaller capacity pump can be employed. This is great for those who are operating off solar power or those who are concerned with the power their Aquaponics system will consume.

Once set and adjusted, an auto siphon will operate flawlessly. By this method the bed is filled slowly and drained rapidly. The rapid drain of the bed is excellent in that it sucks air down through the grow bed media delivering oxygen to the plant roots, to the beneficial bacteria and the resident worm population.
.Auto siphons are employed in all our CHOP systems.  CHOP is an acronym for Constant Height One Pump.
This way of organising the Aquaponics system keeps the water in the fish tank at a constant height and by the use of auto siphons, only one pump is used to move the water from the fish tank to the grow beds and return the water to the fish tank again.


Vid #4 Costa. Sydney Seminar.

Costa of SBS TV spoke at Murray Hallam's Sydney Seminar.
Introduction to growing fresh stuff and why should we do it ?.