Backyard Aquaponics
A place to discuss aquaponics

mcfarm - impressed with your responses I am You have thought it all out well, and I look forward to seeing how it works...with photos

Could you clarify this please Michael... especially in relation to DWC rafts... and oxygenation???

Sorry wasn't very clear, but my comments were about hydroponic commercial systems which I have been studying. Constant flow recirculating commercial hydroponics tend not to use DWC and rafts (haven't found one anyway), and they generally use narrow channels (NFT) that have no reserve capacity for DO. They tend to use just enough water, nutrient and DO to keep the system working well, but because the channels are narrow and shallow they have little capacity for error with DO and are in effect super oxygenated whilst operating. In an absolute power outage that takes out the whole system including backups (lightening strike), the hydro NFT systems will drain dry and kill the plants that way (or if water remains in the system they will quickly run out of DO and often cook the roots too), whereas an AP DWC system will (usually) stay wet, run out of DO and kill the plants and fish.

So the parameters for a DWC aquaponic vs a NFT hydroponic system are very different, and we can't rely on hydroponic experience for DO requirements of plants - that's all I was saying.

Simon, I was planning to use heaps of air in the fish tanks for two reasons; first was for DO for the fish, the second was to keep all the muck from settling so that it moves to the next IBC for filtration. So DO depleted water will enter the FT and be immediately re-oxygenated and I hope this will work???????? I don't think putting the air in the tank immediately before the FT would help, but if it's needed I'll do it.

OBOne, I'll blame you if it doesn't work

Seriously though I need to thank you, as it was your system that got me thinking - in particular your IBC fingerling tanks. Those and the craning in of your large FTs, and the holes for the levels/flows, and filling IBCs with gravel, and all that pipe work. I studied your system and understand why you are doing it that way, it will produce a greater variety of food than a DWC system. But I was still thinking of building channels etcetera for DWC. Then I priced up the commercial pond liner and it was $1500 a roll and thought "I can get 15 IBC's for that AND won't have to dig or make anything - just have to link them together somehow".

When I priced up commercial FTs I found I could get nearly double the water volume in IBCs for the same $$, and as a bonus realized I could run different species and age/size groups in each IBC and pick up an empty tank and move it with ease. Then thought "well if I am going to use IBCs for the GBs why not for the FTs, the filter and everything else?" That left the connections and filtration. The bulkhead fittings will work as joiners, but aren't ideal and something else better will turn up. And the settling/bird-net filtration tank will work too, but there must be a better way. But regardless, the more I looked at a modular IBC system the better it seemed, so I decided I'd better walk the talk, or pace out the plan. No ego involved, too old for that shiite, just want to see if it works, what the problems are that I haven't thought of, and then figure out how to fix 'em.

tehehe



I have idea.

Instead of filling a whole IBC with birdnetting, maybe you could keep your "modular" theme going. Here's what I was thinking.

PVC pipe oriented vertically with birdnetting inside, and air injected down the bottom. This pushes the air (and hence water) up and through your netting and oxygenates it for the proper decomposition process to occur. Essentially a container full of air lift biofilters - except they're more "strainers". So not much different to your IBC full of birdnetting. But the difference is that you can take out one tube and blast it out, take out a different tube the next day etc. Means cleaning it out isn't such a huge job, it's just something you do every day. You should be able to work out how long it takes to get all clogged up and then say "well i need to clean out 2 a day to maintain a clean system".

Just an idea.

Hmmmmmmm, build it you must......

more like "take photo's you must"

this is considered " teasing " , talking about such a big system and not giving us PHOTOOOOOO'S

This seems like an excellent idea.

I like idea. Sort of like a cartridge filter system, remove and replace and clean when you have time. Just build a few more cartridges than directly required in the system.

I think the pipe would be too constrictive and block which is why you'll need lots of them, but what about a larger cartridge e.g. the stackable storage cubes/boxes? Same principle just bigger, and being square will be easier to work with and fit in a rectangular IBC. Yes will definitely give this more thought and play with this idea, thanks.

One of the advantages of the 50mm bulkhead fitting is that, in addition to joining the IBCs together, it will provide an internal female thread to attach to and in the adjoining IBC a male thread to attach to. This means I could direct the water flow exactly where I want it, so into a semi sealed exchangeable filter cartridge for example.

I've got it - milk crates!!!!!!!!! Stuff milk crates full of bird netting and direct the water through them. Rectangular, modular, stackable, removable milk crates. I've even got one or two with solid sides and plastic mesh bottom. Just went and checked and you can fit 18 standard milk crates in an IBC - 3 high x 2 wide x 3 long

Funny how AP gets you excited about milk crates stuffed full of shiite drenched bird netting

Yehhh nice one. Though the problem is that the ones down the bottom might not get replaced often enough - it's dead easy to clean the top ones though, so maybe you can work it so that the tops ones need cleaning quite often, but the bottom ones don't? With a tube (even a rectangular tube) at least when you take the tube out, you take out the whole length.

Maybe you could utilise the washing baskets that OBO used:


Milk crates are certainly a good cheap way of doing it though! (for some reason I instantly thought of throwing in shopping trolleys full of birdnetting.... - seems crates and trolleys are somehow linked in my mind).

Oh. Tells you what, in engineering you have a "LRU" - Lowest Replaceable Unit. Essentially saying if something in that breaks, you replace the whole thing, not just the bit that broke. So what I'm saying is that maybe you could have a stack of crates as your LRU (as opposed to a single crate). Use a bit of packing tape or something to join them all up, and you just lift the whole stack out. Could possibly use a lever mechanism welded to the top of the IBC if it's heavy.

This idea of feeding the world with AP is a good one. However, the harsh reality is that it takes a huge investment. I used the commercial pond liners and in one year I have some leaks in it. Termites as well as fireants can and will chew through. ( I have found a better option that cost half that of pond line and will not fail). I have not had a chance to price out ferocement growing beds. Further, you need a minimum of 2000, more like three or 4000 square feet of growing space, not counting walk way space, to be able to feed a single person for a year (depending on climate and growing seasons). Its actually easier to sell cucumbers from greenhouses and just buy your food. When growing all of your own diet you have to grow several foods to complete a diet, and I question the ability to grow all that a person would need without the addition of sea weed extract or the like to give the plants all they need to grow.

None-the-less, if we all post the data from our harvest then we will be better equipped as a community to meet the challenge.

I wish you the best of luck and success!

[quote="DanDMan"]I question the ability to grow all that a person would need without the addition of sea weed extract or the like to give the plants all they need to grow.
quote]

good morning

if i may
sea weed extract or the like to give the plants all they need to grow


in my system i have never added anything but vermicasting,vermitea,fish castings that i brew,iron/calcium
i have done intensive tests with worms/
my idea is to maintain good plant growth without any outside influence
it works very well.......
now even in this cold/fish not eating i still manage to get good plant growth just using what i am
i believe worms complete the aquaponic cycle
worms and aquaponics go hand in hand
yes you need a lot of worms
you have to keep worms to susstain your size system
possible/simple
me thinking

It all comes down to the feed you use. If you're taking out minerals and micro nutrients from the system within the plant harvest, you have to add these back in again in some form, whether it's in the feed or in supplements, that might be worm casting from external sources, of seaweed extract, or other forms..

Not dead, just sleeping.......... Construction is on hold whilst I build a 10Kw grid interactive solar system. The solar system will be up and running in a month and then work will resume on the AP. The solar system will make the farm a nett exporter of electricity and means the AP system's power usage will be irrelevant in the scheme of things.

Busting a gut to get going on the IBC raft system, but must do the solar first before the NSW feed-in tariff is over subscribed. Can't beat 70 cents a kilowatt for gross generation - the system will pay for itself in 5 years at that rate

Wrote the following in response to OBOne's thread comment ....

Which is exactly the same conclusion I came to with using IBCs for my DWC raft system. That and the bonus of higher water volumes (3 times the volume) for temp stability, and at least 5 times the surface area for growing bacteria on the walls of the IBCs.