Safety in Aquaponics

by gary on January 23, 2010

Interest in aquaponics grows daily.

Thousands of people throughout the world debate the various aspects of this wonderful phenomenon on a growing number of discussion forums and there’s hardly a day goes by when a new book, kit or other product doesn’t hit the market.

But there’s an elephant in the room that no-one’s talking about.

It’s SAFETY!

In terms of people safety, there are two main risks that attend aquaponics systems…….drowning and electrocution.

Several years ago, I pioneered the use of access barriers in aquaponics systems.

One of the reasons I favour square or rectangular tanks is the ease with which they can be covered to prevent entry by curious toddlers.

Access barriers keep toddlers and pets safe.

Access barriers keep toddlers and pets safe.

While access barriers are more widely used than they used to be, there are still far too many systems that are not adequately secured against entry by small people.

If a tank can’t be covered, it must be placed behind a child-proof fence or locked inside a shed.

Nothing will diminish the positive atmosphere that surrounds aquaponics like media headlines about a drowned child.

While small children are those most at risk of drowning in an aquaponics system, electrocution is rather less selective – it will kill anyone.

Electricity - an excellent servant but a cruel master.

Electricity - an excellent servant but a cruel master.

I have seen hundreds of aquaponics systems and many of them have one thing in common……… a foolish disregard for electrical safety.

I’ve seen extension cords running across thoroughfares where they risk damage from being walked or driven on.  I’ve also seen plugs suspended over fish tanks, or lying near puddles, and  I’m aware of people who have built equipment or performed work that should have been done by a licensed electrician.

Don’t get me wrong.  This is not about you…..it’s about us.   This post was largely prompted by a self-audit of my own systems that suggested that I needed to lift my own electrical safety game.

A Clipsal Portable RCD Power Outlet is on my shopping list and a commitment to being smarter around electricity was prominent on my New Years’ resolutions list.

Let’s all commit to a better, safer way of doing things in 2010.

-o0o-

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7 Good Reasons to Remove Solid Wastes.

by gary on January 13, 2010

The accumulation of particulate wastes in an aquaponics system (which largely comprise faecal matter and uneaten feed) will negatively impact your fish in a variety of ways including:
  1. Solid wastes may clog bio-filters and reduce their operating effectiveness.
  2. Particulate matter consumes oxygen during decomposition which means that there is less oxygen for the fish.
  3. The presence of solid wastes encourages the growth of heterotrophic bacteria which (since they grow much faster than nitrifying bacteria) may compete with nitrifiers and inhibit their function.
  4. The breakdown of organic matter in the system will increase ammonia levels which can destabilise nitrification.
  5. Suspended solids may function as a refuge for pathogens while they look for a live host – your fish.
  6. Fish gills can be damaged by solids while breathing or feeding.
  7. Solid wastes will, over time, build up in pipework and fittings and limit water flow.

Not only should solids be removed, but the sooner they are removed in the process the better, because:

  • Sedimentary solids will be churned up and become suspended solids.
  • Suspended solids are more difficult to capture.
  • Small particles leach larger amounts (relatively speaking) of ammonia and other unhelpful substances than larger particles.
  • The longer that solids remain in the system, the more oxygen that will be consumed in their decomposition.
  • The removal of finer particles involves greater expense since the biological treatment of solids invariably  requires equipment and processes which are more expensive than mechanical filtration.

To summarise…….get the solids out of your aquaponics system - and the faster the better.

-o0o-

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Taking Advice

December 14, 2009

The enduring model of skill formation is the apprenticeship system.
It has served humanity for thousands of years and it is the means by which people most effectively develop the skills to do all manner of things including making bread, brain surgery….and aquaponics.
The apprenticeship system comprises three essential elements:

apprentices – whose job is to learn the [...]

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Mythconception #8 – Water Turnover

December 11, 2009

One of the more recent aquaponic myths to circulate is the one that says that the contents of the fish tank must be turned over each hour.
It’s another one of those quaint notions that defies logic.
The fact is that the frequency with which the contents of a fish tank must be turned over are driven by [...]

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Mythconception #7 – Grow Tank Depth

December 8, 2009

Here we go again, the myth makers are at it again. 
This time, it’s grow tank depth for raft systems. 
The suggestion is that grow tanks should be 300mm (12″) deep…..and some of the reasons being proferred for this depth include:

the more water in a system the greater its stability.

shallower tanks may heat up (or cool) down quicker.

shallower [...]

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Vermiponics – Aquaponics without Fish

December 6, 2009

Aquaponics is great.
And the flood and drain model is particularly interesting…..and useful. 
But what if you wanted all of the benefits of aquaponics but none of the complexities of rearing fish?
Or what if you can only grow fish during a particular season?  What do you do to keep your plants going during the off-season?
Well, there is a [...]

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15 Good Reasons to Have a Trickling Bio-Filter

November 21, 2009

Biological filters are the means by which people like you and I are able to grow our own fish.  In short……no bio-filters; no aquaponics!
Bio-filters are simply good places for nitrifying bacteria to live and play.  They provide the optimum environment for the bacteria that convert the potentially toxic wastes produced by the fish into organic plant [...]

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Mythconception #6 – Aquaponics is Easy

October 26, 2009

There are some people who would have you believe that operating an aquaponics system is just…..easy!
The  people most likely to tell you that aquaponics is easy are those who want to sell you aquaponics kits or equipment – so their interest is fairly obvious.  You’re much more likely to sell something to someone if you [...]

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Mythconception #5 – Sustainability

October 22, 2009

We often seen the word sustainability used in conjunction with aquaponics but just how sustainable is it?
Water use efficiency and the absence of herbicides and pesticides are powerful arguments in support of sustainability…..and so is the conversion of fish wastes into plant food.
But these are only part of the picture.
Any notion of sustainability has to acknowledge the following:

The use of wild catch [...]

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Mythconception #4 – Removal of Solid Wastes

October 21, 2009

This ‘mythconception’ would be amusing if not for the fact that it is responsible for the premature death of so many fish.
The purpose of grow beds in a media-based aquaponics system is to facilitate nitrification and to grow plants……in that order.
There’s a prevailing belief among some aquaponicists that an additional function of grow beds is [...]

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