Backyard Aquaponics
A place to discuss aquaponics

Yes it was time to give it up, here's the trial area.



It had run it's course, and it's time to clean up around here, cut back on things that have been and gone and look to new things for the future.. So these went, the solar system (that was hardly ever a solar system) is up for sale, and there have been a few other cheapies going out like the salad bar systems we've had out the back for quite a while.

There's a wrap up of the systems in the next mag which is being finalized today, though it's generally nothing that hasn't been discussed already throughout these threads.

No idea about solids capture. Worm populations were definately bigger in the flood and drain rather than the constantly flooded system, not sure about system 1, I'll have to ask Carl, he emptied it out yesterday when I wasn't here..

I don't think the media was any different in the beds, shouldn;t have been, they don't really get agitated or moved around except when planting and harvesting.

Whats next? No idea at the moment...

There has been a lot of great information about the plant side of things, but what about the fish?

Did any system suit the fish better?

It would be good to know which system could support the most fish, I would suspect the constant flood or the siphon?

All systems were stocked with the same number of fish..... as per the available filtration capacity...

You know what Id like to see and Ive been thinking about this for a while..

3 simple systems, set up as per the trials just completed but on a smaller scale. Lets say, 50L of FT and 50L of media.

1 goldfish in FT.

Media - clear pieces of plastic/bottle lids etc. (emphesis on clear)

System components all clear. Clear 50L tubs for FT and GB, clear pipes etc etc.

Decide on a simple and bullet proof plant to put in each. Something with good root growth. Tomato? Maybe just seeds. Maybe seedlings of similar size.

Test 1. Run systems...... drop food colour in FT at a measured amount and watch how flow, drains and zones through bed and pipes work.

Test 2. Add 1 goldfish per system and measure nitrogen cycles from day to day and see which is the fastest and/ or most effective.

Test 3. Due to clear components we can monitor algea and biofilm growth and where it establishes.

Test 4. Worms. Add 10 worms of similar size and monitor activity. Being a small system (and clear) we might get a better understanding of the worm.

Test 5. Monitor and develope visual workings of water characteristics through different drains. Auto-syphon, flood and drain, constant flood.

Test 6. .....have I missed something




Very simple and manageble systems with rooms with a view..... I am definately going to trial step 1 at home with a mock system. I need to know how water works in a bed through the media.

Sounds like an experiment that a person might do in all the spare time they have

I think everything would turn green rather quickly

Being clear might seem like a way to be able to see things but that does last as Jorgy points out.

Also, uv light tends to inhibit certain bio-filter bacteria and having a system that lets light into the bio-filter and root zone might be difficult. Worms are also light sensitive, too much sun and they die.

Now if you could some how effectively block out light from most everything but the plant, then perhaps you can lift the cover and check things daily to get some use from the trial.

You wouldn't be able to see all the way through the media regardless of what colour/clarity it is. Light will reflect and refract at every boundary, which is why although you can see through a single small glass sphere, you cannot see through a jar full of them.

You can build mathematical models to "observe" flow through the media (or should I say, someone with a better knowledge of fluid dynamics could make the model), MatLab (and other similar software packages) has some excellent tools to help in this regard. Once the theoretical model is built and run, you only need to do a small test with a physical structure to validate the model, then you change whatever model parameters you like and see the corresponding effects.

Modelling pipe flows etc is relatively simple as all the numbers required are usually available from the manufacturer.


Scott

A bit of a necro-bump, but I wanted to say thank you for such an awesome experiment and ask some questions.

Do your day to night temps vary widely there? I think Bullwinkle brought it up, but 24 hour data on temp could be an indicator of why the auto-siphon fish were less voracious. Autosiphon would cause the most air exchange in the media, leading to media closely following air temp? Could drawing cold air into the root zone have explained the slow start to the plants, and the possible larger temp swing day to night have messed with the fish?

In a direct seeding application, would constant flood possibly alleviate seed losses (constant water line would not suck seeds down into depths of media like siphon/F&D)?

Could the longer saturation time of the surface media help establishing initial root ball (CF obviously has always wet but the F&D would probably have more surface moisture than Siphon as the siphon is only full to the top very briefly, while F&D would be soaking the top media for what, at least 10 minutes at a time?) Then as the plants get better root systems they are better able to use the deeper water reserves that are in the bed for a greater time period with F&D or AS, leading to the AS catching up to the others (though maybe slightly initially stunted). I would think the amount of starter soil left on your transplant roots would also affect the water retention>>>root growth, vs starting from seed?

hmm, fish temps, root temps, seeding and root development/moisture/temps... I think those were the big ?'s I came up with, it's taken a bit of time to read the whole thread.

Oh, you (EB) mentioned always adjusting F&D timers to reflect growth stage and weather... so in your experience you would start seedlings in CF and then as the plants grow (assuming it's not too blooming hot) you gradually increase the drain time (eg 60/0 F/D at planting, then 45/15, 30/30, 15/45?) If so that may correlate and backup the above idea regarding need more submersion time the earlier in development, possibly both for moisture and to prevent (cold) air from getting to the roots?

What about adjusting the depth to which the AS drains to? Like, have bell siphons with the 'legs' cut taller or shorter on the bell pipe so that only the top couple inches/half the GB depth/all the GB depth drains? Would make a similar effect to adjusting timer cycle for more/less air infiltration and root moisture. With a slew of uniform GBs it would be easy enough to have a variety of bells that could be swapped out depending on weather/growth stage of the bed.

Thanks again for doing so much work to benefit the community! I've been learning so much reading these big long matured threads.

@EB you published the amount of feed that you fed the fish and the amount of water that the trials used but did you ever publish the yields of fish and/or plants?

I think Charlie had a good idea, but would have to keep things covered as already pointed out or the algae and UV inhibition of the bacteria would bring it to a swift grinding halt.

This last experiment was on GB styles, I suggest a test of GB types. Setup same volume same stocking FTs, route through an RFF, then onward to one system with a media bed, one with DWC and one with pipes/vertical beds. Use the same plants and see which method best uses the nutrients and produces the most output. The solids can be drained from the RFF for mineralization and re-addition to the system.

Looking forward to seeing what will fill the space, keep up the great work guys.

Some years later
Unfortunate end to this wonderfull trial.
No power consumption results
No actual fish yeild results (Fish weight at end minus fish weight at start)
No waste build up idea in final bed deconstruction
In fact some even found out from others that the trial had been ended from another post.

After reading this entire post ( some parts of it more than once) I'm left a little disapointed.
It's a shame after such excellent dedication to this project for the first 12 months that at the end there could have been so many questions answered with some photos and some final measurements made/taken that weren't.

However I for one still have learned a lot form this trial and applaud Joel and his staff for running it and brushing off the dirt dropped on him from other sources and continuing the trial.

Great read, thank you for the experiment.

I have a decent setup for a similar experiment, all being fed from a common FT and irrigation line (I have timed hose valves for each bed, allowing each to be irrigated simultaneously or independently from each other and at whatever intervals I choose). I chose this particular setup to be able to run the pump continuously. Another advantage of this is that my turnover rate through the GBs is irrelevant as the FT is pumping 24/7. All water into the beds (other than transpiration and evaporation) is returning, and all excess water not currently feeding a bed is looped back to the drain line back to the pond.

...Well, I guess this isn't entirely right. I have 600+ gal "pond" with a 1200GPH magdrive pump, with about 10' head height, so that might not actually be turning over every hour, but it's fairly close I think.

As my inner systems engineer troubleshoots the system, I will post more about

I think my "inner systems engineer" is awol (can someone please motivate me? I have my growbed in the shade side of my house, and it doesnt grow anything )