Backyard Aquaponics
A place to discuss aquaponics

That's it in a nutshell...

I converted the 200 litre swirl filter by removing the T and the two elbows,then by fixing a pail over the inlet standpipe i was changing the direction of flow in a downwards direction,hopefully forcing the TSS onto the bottom of the barrel.But maybe my standpipe was to short,pail to small to big but there was visibly more particles making it back to the outlet,so i converted it back,this time with slightly more angle on the elbows.
The 60 litre barrel will keep its shade cloth to clean the water going to the tubes.
I have used plastic mesh rolled into tubes,and placed in the flow in a large settlement tank,they did a good job along with fine plastic brushes of knocking larger solids out of suspension.Cleaning required opening the bottom drain and just lifting them out,most of the solids would fall of back into the tank,a quick rinse with a hose and they were placed back in the tank.

This is advice or at least an observation that I've already made to NA but how can you be serious about a commercial venture that includes aquaculture but be so ignorant about the methods and technology used in commercial aquaculture?

There is nothing wrong with trying new ways and ideas but even if your plans "work" how are you going to know?

It is not enough to grow fish and plants you have to asses your results against what can be achieved using other methods, other resources.

At the moment you seem to be forging ahead and lets say you develop a system that can grow 20t of fish and 140t of veg using x amount of water, y amount of electricity, z amount of labour and costs a certain amount to build.

How are you going to know if what you have is better than whats already being done if you don't know whats already being done and don't know how they do it?

For someone to be talking about a commercial operation that includes aquaculture and not know what liquid oxygen is used for just beggars belief. What else do you not know that you should?

Do you have to have a commercial operation that includes liquid oxygen? Certainly not, but if you are ignorant on the use of liquid oxygen are you also ignorant on how to calculate your oxygen requirements? Do you know how to calculate the amount of oxygen your system will need? Can you design a system so that you can be confident you won't need liquid oxygen to maintain fish health? What backup systems will you have installed and how will you design them to ensure that fish do not become oxygen stressed if the back systems are needed?

These considerations don't matter for a BYAP because a hobbyist can always get a bigger air pump or feed the fish less. A commercial grower can not afford such an imprecise laissez faire attitude unless they have money to burn.

+ 1 Stuart!

I think the problem is people think that raising a lot of fish.. and/or plants... is simply to make what works in a small backyard system.... bigger...

I don't think people realise the compromises that are made in small AP systems... and how close to they are to being detrimental to fish health/welfare... or even survival...

Although many have found out the hard way.. by overstocking their fish...

It's probably also compounded by the extremely forgiving nature of the Tilapia that many stock...

Likewise I don't think that most people realise the scale.. and labour intensity.. required for any real volume of plant production... and again just think it's a matter of making things... bigger....

I've said it before.. and Stuart and others are echoing it.... we blissfully define aquaponics as a combination of aquaculture and hydroponics...

Then somehow get so wrapped up the the fuzzy romance of it all.. that when we think of going ... bigger...

We totally ignore almost all the proven knowledge.. and designs... of both the aquaculture and hydroponics industries...

And in a romantic desire to believe that aquaponics is somehow so much different... than what we define it as... try and do things differently than the same two industries have painstakingly research and developed for decades...

I'm not against tinkering and experimenting.. I do it all the time in the backyard...

But why would you do it.. in a commercial sense....

Why would you not just grow your fish.. the way commercial aquaculturalists do... and grow your plants the way that commercial hydroponicists do....

And just combine the two... with the nutrient rich water... it's the only common denominator... and has always been so... in reality... and by the very definitions we have accepted... and so proudly proclaim... as so "wonderful".. and "beneficial"...

It's not rocket science... and the science of both aquaculture and hydroponics... is pretty well sound and complete... and.. available...

Ah yes, the Aquaponics for developing nations vs Aquaponics from a developed nation.

It boils down to the fact that I want 3000 other locals on my island to get involved would mean I have to design systems with components recycled from the food shipping and handling industry. We import 90% our food.

I would love to read the yellow guy got close to one once but don't have access to one would love to read what he has to say about AP for developing small island states. Even if it doesent mention this in detail any info I can get my hands on I will take what I can from it.

My aim is to get a average weeks pay for my labour from a solar powerd system that I don't have to dig holes in the ground for.
The thought of using recycled components to archive economic freedom is a slap in the face to the man, one I want to personally delevier.

I also like to talk AP, so keep those ideas coming, witch brings me to

It looks like LOX is used only in one place as a tech showpiece. This is Murray's take on LOX
Very interesting discussion on filtration and stocking.

Filtration/Aeration/Feeding - take care of these three things properly and one can aim to achieve higher stocking. I am looking at 50 kg/1000 L as a decent start in a commercial sense and experts can look at other challenges in the range of 100-125 kg/1000 L. IMO
Or, do you think 50 kg/1000 L itself is a big challenge for AP beginners?

dasboot

I hope you did not restict the up flow of the inlet any by putting the bukets bottom under the static water level, IMO you should allow the inflow to disrupt surface tention.

That's simply not true.... and as noted by Stuart earlier... just betrays your total lack of aquacultural knowledge...

While LOX may not be universally used... other forms of direct oxygen injection are universally used to enable high stocking densities...

And the various pictures of Tilapia swimming around tanks like sardines in a can... attest to that....



Again not exactly true.. and potentially misleading...

Murray is commenting on the Green Sky Growers operation... a high tech showcase system... (as he says)... that was never commercial.. by their own admission... and has long since closed...

Yes Green Sky Growers did use LOX.... but Murray was commenting on the "operation"... not on LOX specifically... of which he would not have had any knowledge basis to comment anyway...

http://www.aquaponics.net.au/forum/arch ... -3748.html


Not without direct oxygen injection... IMO.. barely even at the 50kg/m3 end of the scale... and completely impossible as you extend above that ... read some basic aquaculture theory... or even basic science theory..


It's not just a "big challenge" for AP beginners... it's both unnecessary.. and unadvisable...

And we've been saying so... for years... please do not advise "beginners" to even attempt to stock at those levels.. even with Tilapia... unless you address the design of a system from a total RAS aquaculture perspective...

No unnecessary,you are just redirecting the flow taking the solids with it,these should then settle out leaving the cleaner water to exit through the outlet.The inlet should be high enough to prevent the water flow from keeping the solids suspended allowing them to making to the outlet.

Build a radial flow filter to the specs shown in the two Earthan Group links above... and it will work just fine...

Well for me these radial flow filters will also split the water 4 ways,hope fully the increased perssure drop and quite friendly :lol: increasing retention time may work in my faviour. I think by letting the water flow up until gravity can pull it down removes lots of energy from the strength of the waters flow and allow for faster settiling of solids (the water and solids fall at different rates) as opposed to disrupting the up flow before gravity gets to it.

Really what Rupert said.

I used there principles,but because i can’t get unseals and the through tank fittings i can get won’t seal through the side of a 200 litre barrel,the faces are to small on 3inch to pull the barrel straight, i built it with bottom fittings,so its my take on there filter. After reading the PDF i did do a quick experiment with different layouts,giving me the confidence the my filter works well for me,maybe slight tweaking will help,but with the amount of poo its taking out everything it takes out is better out than in, between the swirl and the filter barrel for the tubes,there are no particles in the tubes.

There's nothing wrong with a swirl filter.. if it's doing the job Dasboot...

I've used tank bulkhead fittings successfully with barrels... before uniseals became common...

Thanks Rupertofoz,one of those on going trials that one day i might get right... :thumb right:

Our fittings only have a very small face,its a nut with the smallest width at maybe 3mm ,because or the radius of the barrel i don’t have the confidence that it will pull the barrel flat to seal.The 2 inch on the 60 litre did,but scared to risk the bigger barrel.