Aquaponics "Mythconceptions"

[GaryD]

Hi Paul,

lol it may seem like I disagree more than I agree but I have a passion for seeing that fish health is accounted for and what I see in aquaponics scares me. I am not a trainer and do not suggest my methods of "getting the message across" are not abrasive. The message is clear and difficult do misinterpret. And I had nothing better to do this week end, home with the flu.

Your illness works to our benefit. May you return to good health quickly.

Less intensive methods of aquaculture have persisted for centuries and aquaponics is simply the latest incarnation of non-intensive aquaculture.

While I share your concern for fish health (particularly my own fish), I'm optimistic about the future of backyard aquaculture. The current topical interest in aquaponics means that more people (from developed nations at least) are growing food fish in their backyards than probably at any other time in history.

Everyone is feeling their way to some extent. I feel that, if aquaponics can do for aquaculture (in a backyard sense) what the free range/organic movement has done for the egg and chicken meat industries, it will be a worthwhile journey.

As with the chicken example, we need a less expensive, less intensive model for the production of fish and vegetables. We should attach to the best that the aquaculture industry has to offer while taking advantage of any opportunities that the scale of backyard aquaponics has to offer.

Very soon I believe. On other hand, I have a small barra hatchery (one of my great designs) to install in the next few weeks in logan village which will turn into aquaponics later, perhaps you would like to come along. You may get some ideas....

Great! Always open to new ideas.

Most forums. Even this one has prominent members offering unqualified and incorrect advice. What is the average joe to make of 1kg of salt/1000L to treat a minor nitrite issue as a general mystical equation for example...

I've read (and provided) that advice on several occasions. I've had fish that have appeared listless suddenly come good with the simple addition of some salt to their water. Was it my imagination?

Please tell us more..........sans the pontification if you please.

What is a professional, well that is a good question. I am a professional. I make a living out of successful commercial aquaculture design. Am I am expert? Not even close. Does this make me an aquaponics professional? No, though it does mean I am more than capable of designing an efficient fish system that you plug your plants into.

I'm looking forward to your demonstration of your professional abilities......particularly given the ease with which you take other people and their ideas to pieces. My acceptance of someone's assessment of their own abilities is very much a short term thing with me. Sooner or later, they have to show me. It's the trainer in me.

Gary

[DaveOponic]

Crusty,


"On other hand, I have a small barra hatchery (one of my great designs) to install in the next few weeks in logan village which will turn into aquaponics later, perhaps you would like to come along. You may get some ideas...."


I'd like to hear more about this. I buy my Barra fry from a hatchery here in Brunei. The manager of the hatchery gave me a full guided tour of the whole operation, including introducing me to the "brood stock" a few of the biggest Barramundi I have ever seen in a pond. The hatchery is between the beach and the river and seawater is pumped into the breeding ponds.

When I asked about the possibility of breeding Barra in my tanks at home, he laughed. Do you live near the beach? Was his reply. If not, almost impossible.

I have managed to raise Tilapia over the past three years in my AP tanks. (Not much to that) But from what I have seen and read, breeding Barramundi, even in tropical Borneo, is a whole new challenge.

So. Having seen how Barra are bred commercially, I am intrigued to read your post quoted above. If I am not mistaken, Logan Village is a shopping mall (?) in Brisbane. It is going into winter, so you would need water heated to around 28 C (optimum Barra temp.) and available saltwater at correct salinity etc.

Actually, I will be in Brisbane around 6th June and would love to see your "great design" Barra hatchery. please post more details.


Dave

[DaveOponic]

"Most forums. Even this one has prominent members offering unqualified and incorrect advice. What is the average joe to make of 1kg of salt/1000L to treat a minor nitrite issue as a general mystical equation for example..."

Crusty,

I've been a member of this forum (and its predecessor) for a few years now. I take everything with a "grain of salt" (sorry....couldn't resist) but when I first read about adding sea salt as a fish tonic, I was sceptical. My tanks are 1,000 litres and the thought of adding a whole kilogram of salt once horrified me.

A few years later and although I rarely need to use salt, it is a trusted and safe means of avoiding disaster when I spot a sick fish in the tank. I have probably used salt only two or three times in three or four years of AP.

When I restocked recently with Barra fry from the hatchery, I brought home quite a few litres of seawater to slowly acclimatize the Barra to the fresh water. Gradually over three or four days I added fresh water.

As I now understand, and I am by no means an expert.... many freshwater fish are able to swim in various concentrations of brackish and salt water without ill effects. I don't fully understand the chemistry or physiology of this but common sense tells me that a high concentration of salt or a sudden change in salinity can be harmful to fish.

So, I am pretty much the average Joe. By no means an expert or a professional in Aquaculture. I don't always agree with what Gary has to say or how he says it and have had differences in the past. I do respect his experience though and his dedication to AP and Micro-Farming in general. He has certainly taught me a few things about the importance of filtration in particular and system design in general.

As for other members of the forum, I appreciate the range of experience, both beginners and old hands alike and I will consider some ideas and maybe reject others. Mystical equation? No. More like a useful rule of thumb, an approximate guide that is quite a practical guide for home AP'ers who have sick fish and want to do something to keep the system running and restore the balance.

Look forward to learning more about your Barra hatchery.


Dave

[Crusty]

So. Having seen how Barra are bred commercially, I am intrigued to read your post quoted above. If I am not mistaken, Logan Village is a shopping mall (?) in Brisbane. It is going into winter, so you would need water heated to around 28 C (optimum Barra temp.) and available saltwater at correct salinity etc.

Actually, I will be in Brisbane around 6th June and would love to see your "great design" Barra hatchery. please post more details.

Sorry, it is a nursery, not a hatchery. I believe he plans to run it saline, at what level I do not know and the water is to be heated as needed. This is only a small unit comprising of 6 x 2kL tanks, part of a bigger plan I expect. Keep in mind, I design them, I do not run them. How he ends up running it may differ from the intended design. I have no issue with inland salt water operations. We built a black cobia/seaweed pilot inland, that trucked sea water in, last year. If the owner permits me to post photos, I will post them.

I visited a 150 tonne RAS farm yesterday and they breed their own barra (they have some albino ones!) and they are no where near a river.....

My tanks are 1,000 litres and the thought of adding a whole kilogram of salt once horrified me.

The 1kg of salt per 1000 liters was used in reference and advice to treating nitrite of 0.25ppm. It is overkill by 100 times and not needed. I have provided the accurate measure by which to treat nitrite in another thread. If you want to run salt continuously at 2ppt, then do so, is it needed, no.

[GaryD]

Noah, who reads my blog, has responded to my posts on grow bed depth.....and he poses some questions......

I am curious as to what the advantages are over 300mm beds and would like for you to show me where i could find them. Or could you tell me what they are.

Noah, the discussion on grow bed depth starts with the fundamentalist position that grow beds must/should be 300mm deep.

My position is that they can be less than 300mm and that, not only will they work just as well, but that there are distinct advantages for having them less.......and I detail those advantages.....here.

Wouldn't it make sense to use the beds (whether it be 150mm, 300mm, 600mm) that provide the most possible positive outcomes for you at the most cost effective price?

Absolutely!.....and that's the very point that I seek to make. Why expose someone to the expense of a particular option if they can do the same thing for half the money? Ask yourself.....whose interests are being catered to by such behaviour.

The reasons given by the "Fundamentalist" appear to be quite sound. Where can i find the info to refute there cases?

The better question is where can you find empirical information to support the "reasons"......which authorative researcher has come out and said anything that supports the choice of 300mm over anything else? When the "reasons" are exposed to logical or scientific examination, they simply don't stack up.

I would much appreciate your guidance in this as i would like to make sure that i have a balanced view of what Aquaponics is and what i really need to be made aware of before i commit any serious dollars to my self sufficient dreams.

I'm happy to help you in any way that I can. Aquaponics is easy enough to do if you take the time to learn the basics and avoid being distracted by the 'mythconceptions' which have more to do with marketing and less to do with practical backyard food production.

Gary

[Erich]

Gary

I like your details on "Mythconception #3 – Grow Bed Depth" - however some people still push that this is the magic number. Im still relatively new to this however agree with what you say here

The only thing I can see on deeper beds is the ability to hold up very mature larger crops better due to the depth the roots can grow (corn/tomatoes etc)

[GaryD]

Hi Erich,

Thank you.

.....however some people still push that this is the magic number.

Those who push them hardest just happen to be the same people who sell them.

The only thing I can see on deeper beds is the ability to hold up very mature larger crops better due to the depth the roots can grow (corn/tomatoes etc)

Sweetcorn is an unusual plant when it comes to media-based grow beds. If you use clay pebbles, it doesn't matter what depth you use because the slightest breeze will bowl it over.

If you're using gravel, as little as 100mm will keep it anchored.

The reality is that sweetcorn, like root crops, potatoes, melons and pumpkins can all be produced in grow beds......but would be much more cost effectively grown in soil-based options like wicking bed.

A 600 litre grow bed filled with clay pebbles costs at least $800 by the time it is plumbed up and on a support stand (it can exceed $1,000 depending on whose bed you buy and how you set it up).

Growing a large tomato bush that occupies half of such a bed is going to produce very expensive tomatoes indeed.

Tomatoes are often touted as being plants that need deep beds because of their large root mass. The fact is that tomatoes grow roots to fit the environment in which they are being grown. They are grown in grow beds, raft tanks, NFT systems.....you name it......and one is as good as the other.

Gary

[Erich]

lol - exactly what I thought

Love the forums - straight shooting and up front

[bigdaddy]

Hi folks,

I asked the same thing as you Erich,from many people,and the common thread I get is,depth is not necessarily the criteria,but the capacity to filter effectively is the criteria.In my barra system I just have cottage pebbles in my grow bed at about 300mm deep and all the plants grow well in it.I decided to run my tomato bushes through winter which was not successful as they got blown over one stormy winters night.

In my trout system,I have cottage pebbles with about 1/3 of the length is top dressed with clay.I run cos lettuce(along with other plants) in both,and find they tend to fall over a bit in the clay section plus I think the lettuce and other plants grow better in the pebble section only.That is also about 300 mm deep but only because I think it will suit the plants I put into it.Might put some deeper grow beds around the place same or shallower.will possibly do a raft and NFT later on as well,so yeah.I keep to 300 mm as my rule of thumb but I don't really care how deep it is so long as I have enough filtration for my system.

BTW what was that formula for aphids you mentioned the other day?how much molassis Seasol,say in a litre of Dipel and water mix?

Cheers.

[timo]

'Only by optimising the water quality in an aquaponics system, can you maximise its productivity, and you can only optimise water quality in a small aquaponics system by removing the solids.'

Bravo!