Aquaponics - Worms

I've been growing a tomato plant for over a year (I think) now, and it's been looking very tired over winter. It was originally in my grow bed with a bell siphon, but at the end of the season I decided I'd pull it up, that was six months ago. In the interim, it's been sitting in a bucket under the input flow to that same growbed, and as far as I knew there was no media for it to grow in, just a stack of roots in a bucket with a drain hole half way up the side.

It looks like this now.

It's seen better days.

It's not quite as dead as it looked, and there are still a few patches of life in various places, but it's definitely time to retire it.

It had quite a bit more green on it only a few days ago, but I cut all the healthy bits off in an attempt to get them to strike roots by sitting them in the fish tank. There's even a few tomatoes.





For some reason it didnt work, even though normally it does. Rather than striking roots, the shoots just all died off.

But when I had a look in the bucket it was living in I found there was actually some media in the bottom. Around a quarter of a 10L bucket of scoria.

But interestingly, I also found these.

Pictured herein what apears to me to be zero gravity are a large handful of some of the most insanely lively worms you ever did see.

All living entirely under water for ever.







I accidentally left them in the water I had them in to take this photo, and within only a few minutes, they had turned from the liveliest bunch of worms to a very sleepy bunch of worms that I'm guessing were not enjoying living in the still water without the dissolved oxygen levels they had enjoyed before.

I think I found them just in time, and have put them into a container with some rotting vegetation to become the first inhabitants of my worm farm. They took nearly five minutes to dig themselves into the ground whereas when I was trying to get them out of the scoria, I sometimes chased a single one for what seemed like five minutes.

It seems worms like to breath.






120 Things in 20 years - Discovering the obvious about Aquaponics and worms.

Aquaponics - Karmic debt

My karmic credit must have been good over the last 24 hours.

Two potential system disasters averted by a stack of luck, and a few minutes.

The first was yesterday, and involved my NFT tubes being fed too much water, and getting too heavy at one end. The flimsy stand they are now on was even more flimsy yesterday, and it gave way. The result was 3 horizontal grow tubes all standing on end, in a desperate attempt to mimic their strawberry tower cousins on the other side of the grow house. The pump was delivering between 50 and 70 litres per hour and was, of course, carrying on as if everything was fine. Lucky for me, I happened to be out there and quickly made myself into a table and called for help to turn off the pump.

A close call.

This morning I went outside and found water all over the floor and a steady flow from the strawberry towers to the ground.

That's often a bad sign in aquaponics, but it was still flowing, a flow is a good thing in aquaponics.

Flow is a better sign than flood is bad.

Which is nice.

The water was flowing freely out of the lowest strawberry hole on the first strawberry tower.

The culprit turned out to be two small pieces of scoria that had found a way to block the exit hole.

I saw them in there the day before, but for some reason didn't do anything about them.

I've since removed them.

The fish tank got very low.

Low enough so that a fin was out of the water on my biggest fish.

But not quite low enough for the pump to start sucking air. I still had half an inch of water before that happened.

Given it was only the water from one strawberry tower, I figure I had about 15 minutes spare before the pump would have been damaged, and the fish would have been walking.

We all know fish hate walking.

This is what's known on the forums as an HSM!*

I was very, very lucky.

Twice.

Still there was the problem of water. Refilling the system from the tap would have been just as bad for the fish as not having water at all. They would all die from temperature, pH, and chlorine shock.

But I managed to scrounge some water from within the system.

I turned off the strawberry towers, and the NFT tubes. I run the NFT tubes half full of water so there was around 10 to 15 litres there. I also took the stand pipe out of my grow bed and let that drain completely. That gained me another 30 litres or so because I run a shortened siphon so that the bottom 3/4s of the bed is in constant flood. I also had the water from the duckweed tank. That is what saved the day, because although now nearly empty, it had been topping up the fish tank water until the end of the hose found air and the siphon broke. But I drained what was left of that and added that to the fish tank as well. That got me an extra 20 litres or so. I also added 5 litres of water from a plastic tub I filled a few days ago. So most of the water was already system water, so the fish shouldn't have any problems with it.

My final recovered level looked like this.

Which was a pretty good result and would allow me to turn the system back on.

Success!

Way too close for comfort.

But...

This is what the water looked like.

Not so nice

But I soon noticed some fish.

And then this.

Total time between these three photos was...

37 minutes and 19 seconds as checked by their time stamps.

I thought I was in for days of trouble followed by sick fish.

Everyone seems happy and (I think) all is well.



I need a solution for this kind of thing, and it was crazy of me to not have a second exit flow from each strawberry tower.

So close.


*Holy Ship Moment

Aquaponics - Ultra slow flow siphon solution

I came up with two solutions to attempting to make a small bucket that takes an hour to fill, but then dumps quickly, as discussed in the previous post called "Aquaponics - Ultra slow flow siphon problem".

The first came through a deliberate approach with a tested methodology, the second came because I recognised the first as already existing. (It made me think of another problem, leading me to find another solution, and that looked a bit like a deer scarer)

It's a deer scarer.

Actually the first solution is also a solution for some other problem, so I think I'll save it for solving that.

A deer scarer works by having a tube pivoting around a point roughly in the centre like a set of scales. One end is blocked and made slightly heavier. The other end is made slightly longer. Everything is set up in such a way as to make the thing sit with the open end up.

If you add a trickle of water to the open end, it eventually fills the tube. when it does it reaches a point where the water in the longer end overcomes the extra weight in the heavy end, so it tips.

Thanks for the use of the pic Cassiopeia_sweet

It looks like this.

Genius.

Once the water is dumped, the heavy end thumps down onto a stone making a pleasant (yet apparently scary to deer) sound, that eases you into the now.

My version would be quiet.






My version would also be less graceful. If you made it out of 200mm PVC tubing you could dump a bucket full of water each time in a short compact unit. You could also place it somewhere else and pipe the sudden dump of water to your grow bed.

So...

To make a grow bed flood for most of an hour, drain suddenly, then flood again, this might work.

Create a bell siphon that has a standpipe too large for your pump's flow. This will mean the siphon wont trigger, but the standpipe will allow water to circulate back to the fish tank or sump just by normal overflow through the standpipe. In other words, it will act as a constant flood grow bed.

Next mount a deer scarer above the siphon and divert a trickle of water from your pump to it, so that it tips once an hour (add a tap on the outlet for adjustment).

The sudden rush of water into the siphon area will be enough to decisively trigger your oversized siphon, draining all the water in mere moments to everyone's delight. So now we have a "mostly flood, and some drain" system. We also have an interesting, steam punk, bit of low tech kit moving around, rather than the sedentary vista provided by a constant flood grow bed.

This could be configured so that your grow bed drained every 12 hours or any desired time, making sure you had no dead areas of rancid mush hiding in the corners of your (almost) constant-flood grow bed.

Thanks Japan.

Thanks deer.

Thanks Nom*.

*[note from the future - someone has created an excellent example of just how such a thing might work.
http://www.youtube.com/watch?v=GSXqr3VdYyM
and I love it when someone goes to the trouble of making something out of clear plastic just to show us. 
http://www.youtube.com/watch?v=4oS0mNApYqw
Thanks for the heads up Nom. ]

Aquaponics - Ultra slow flow siphon problem

For some time now I've been working on an approach to invention and problem solving that, in my house, has become dramatically known as "The Invention Engine". It's a formalized structure to problem solving, and so far it's been working very well. It's all in my head at the moment, but at some stage I'll put it out to the world in some form. I'm testing the process again by finding a solution to triggering a siphon with an ultra slow flow.

In some recent trials, it looks like there may be some advantages to a constant flood grow beds, rather than flood and drain. This relies on having highly oxygenated water, but you should have that anyway because that's what your fish like. Some plants prefer flood and drain, but a lot seem to enjoy constant flood.

I can't help but think that one potential downside to constant flood, is that there may be areas that could  become stagnant. Flood and drain, on the other hand, pulls all the water out on each cycle, so there are no areas that miss out on turnover with new water. My fear is that it might be possible that constant flood could leave some areas to could go rotten over time.

I thought I might make a grow bed that was constant flood for most of an hour, drained once quickly, then have it repeat that pattern for ever.

Tricky.

Constant flood works by having a standpipe sticking up through the bottom of your grow bed at the height you desire the water to sit. You pump water in constantly, and it overflows into the fish tank via the standpipe.

So my solution would be to put a bell over the standpipe, but with an oversized standpipe that would be too big for the flow, so that it didn't trigger.

Now all we need to do is introduce a new, quick flow of water once every hour to trigger the siphon.

The Invention Engine first casually mentioned I should just put a second pump on a timer, and have it supply the hourly additional dump of water. I told it that a solution like that was too easy and expensive, and really needed a rethink.

I added the following parameters...

1. that it should require no additional pump
2. that it should require no electronics or timers

The Invention Engine suggested I divert a flow of water to a bucket sitting over the grow bed, put a second bell siphon in it, and have the water dump quickly to trigger the main siphon.

"OK" I  said. But how do you make a siphon that takes an hour to trigger, but still delivers a rush of water to the grow bed. A siphon with a very slow inflow can only trigger if it had a very small standpipe. Any flow that took an hour to fill a bucket, would only trigger a tiny siphon, and only deliver a tiny amount of additional water to the grow bed. A tiny additional flow would mean some very accurate calibrations to make the grow bed's main siphon trigger. In fact it might not be possible, and would definitely not be reliable.

"Make it huge" The Invention Engine replied.

"I want it small" I insisted.

"Oh" said The Invention Engine, "A small bucket that takes an hour to fill, but then dumps quickly?  That's a different question altogether".