Backyard Aquaponics
A place to discuss aquaponics

mattyoga

Rats

I have chickens so know all about them.
3 tips you may think about

1 I found that minimizing food supply is often required. I removed the chicken feeders every night for 3 days and they started on the baits, admittedly that is usually in autum/winter when they start storing food...

2 Smear the solid baits with nutella, just a little for scent They have trouble resisting this.

3 The trap you set may be working, ie they may fall in but as they can jump nearly a meter vertically they may be getting out. Add some water to the bottom 20 cm to prevent them from being able to purchase for a jump. (not sure how high the blue containers are...)


I have been viewing this forum for some time, set up my own mini system using all the tips I have read from people like yourself. Trouble shooting brought me across your excellent updates.... I could not resist offering a little help to someone who seems to give a lot...

GL

Thanks for the tips - they seem to have gone strangely quiet in the last few days, though I don't think they have touched the baits - I have been avoiding checking the ones I can't see clearly so as not to put them off so they may have eaten them. I'll try the nutella on the bait trick.

With all the toms, carob and duck food gone at night they can only eat sour grapes at present - I'll take those down soon as well.

Papaya is going nuts!

Has been flowering and hopefully setting fruits. Not bad for 3.5 months growth!
Also got some beans in to replace the Tom's. Hope the rats don't eat them.

Not sure what to do with wicking bed at end with failed corn crop. Will either convert to ap wicking bed, or make it full gravel. . .

Hi mattyoga,

You probably already know this but it looks like the corn failed from a shortage of Potassium. I'm basing this on the look of the leaves and the overall small size of the corn plants. Here are a couple of things to look at, I think you may have seen one of them and possibly both, but just in case -

http://www.thefieldposition.com/2012/06/potassium-deficiency-is-growing-problem-in-corn/

https://www.ipni.net/ppiweb/bcrops.nsf/$webindex/84CBB51751971AB3852568F000673A10/$file/98-3p04.pdf

I had this happen to the corn in a wicking bed last year so you aren't alone.

Cheers

Thanks for the links Scotty - had not seen the second one. Could well have been K - I had broad beans in there before so there should have been plenty of N - I top dressed with Blood and bone and pellitised chook manure before planting the corn, though maybe I should have used a bit of sulfate of potash.

The wicking bed does not wick very well - has got clay balls at the bottom - seems to only wick about 20cm high so the corn may not have got into the water very well (especially if the roots are poorly formed due to K deficiency). I don't bother with a big layer of media at the bottom oy my wicking beds now - just put a reservoir in, a small amount of sand then out the soil over the top.

I'll either rebuild it as above, or try another AP wicking bed (leaning towards that at present)

So I'm guessing things improved with the inline wicking bed since your last post two years ago.
Did you make changes to it?
Any pics of the current design?

Yes - need to do an update. No changes made, other than adding a sprinkle of rock dust and lupin mulch twice a year. I'll take some snaps over the next few days. Might have been a case of the microbiology took a while to get going in the soil, though now its going it produces more stable crops with minimal deficiencies.

Looking through the previous posts, just wish to make sure I'm not missing anything.

Water from FT flows directly into bottom of Inline Wicking Bed.
Double layer of shade cloth (anything under it? like gravel or river rock?)
On top of the shade cloth is 5 layers of cardboard (about 300mm?) am guessing for carbon in system as it breaks down.
Then on top of the cardboard is a mix of mushroom compost, soil and sand. How deep was that layer?
The water level is set by the outflow pipe which has a slot cut in it (at about 250mm?) and then that empties into the sump, which is then pumped back to the FT. No additional filtering.

Am really keen to do an inline wicking bed. Don't mind the water getting tannins, but don't want solids like soil and sand going in the Sump and FT.

Was thinking of cutting an IBC in half, (about 500mm each). Have a slotted 100mm PVC pipe along the bottom with slots facing down, connected to an elbow at one end, which then goes up the interior side of the IBC and connects to the pipe coming from the FT.
Cover PVC pipe with a 200mm layer of gravel. Cover gravel with shade cloth, or old bedsheet. Put a 150mm layer of cardboard ontop of the bedsheet. Then fill remaining 150mm soil/compost/sand mix. As the carboard breaks down, add more soil/compost mix.
I would put a Uniseal about 200mm from the bottom, so the water exits just below the bedsheet, via a PVC pipe in the uniseal, and back to the sump.

How does that sound?

Also, is the water going to the inline wicking bed on all the time or on a timer?

Yes - water is on a flood and drain cycle. I would not use a bed sheet as if it is cotton it will just decompose. I have experienced some blocking in the media when a fish died and its remains got sucked down into the gravel bed - If I was to do it again I would do some solids filtering before sending water to the hydroton media at the base of the in line wicking bed. There is about 100mm of hydroton on the base, then shadecloth, then cardboard (about 50mm thick - now all decomposed), then about 300mm of soil mix - make sure there is enough mineral content so that it does not collapse - I just added more gutless Perth soil (sand) to the mix to get the right consistency.

If you are not relying on the gravel at the bottom to provide biofiltration it does not have to be that deep (i.e 200mm of gravel may be a bit of overkill unless you need it for bio filtration). I would also suggest doing a bottom drain with standpipe arrangement rather than side uniseal as this allows the water height to be changed if required and allows access to clear roots etc and fully drain the bed between cycles, thus promoting more aerobic activity.

Thanks for the reply.
So the pump in the sump is on a timer I presume. Or did you rig up an auto siphon on the Wicking bed?

Good point about the bedsheet. I have some shade cloth lying around, so will use that.

At Present all I have is a single IBC cut in two, with a 254mm growbed above the FT. The growbed has in hydroton, and is on a autosiphon. A pump in the FT pumps the water into the GB above, and it empties back into the FT via the autosiphon.

My Nitrites are running very high, but have no room in the growbed to plant further, so was looking at expanding the growing area. Came across the idea of a wicking bed, and I liked the idea of that, but knowing me, would likely forget to top up the reservoir and the plants would suffer. Then I came across the inline wicking bed, and thought that would be the perfect solution.

How did a fish get sucked through your SLO with the guard you put on?

Ok, so being that I have the hydroton GB, I can use less gravel in the base of the wicking bed. So maybe 100mm to cover the pipe along the bottom that delivers the water.
Good idea about the bottom drain....guess a bulkhead fitting could work for that.

Thanks for the suggestions.

The fish got through the SLO guard in small bits - i.e. once it started breaking down the bones and scales etc got sucked up (I'd emptied the system of trout though missed one and it dies when it warmed up).

If you have high nitrites your biofiltration has not cycled, more plants will not help with that. From the drawing it looks like you have about 200L of gravel above the sump, with 100L each in the wicking beds. that would be about 350L of wet gravel allowing a max of 14 fish to be on the safe side stocking density wise.

Yes my system is on a timer - not a fan of siphons.

With what you have drawn above - I would be concerned about too much solids going into the wicking beds. I would consider either (in order of pref):
1) adding some basic solids filtration
and/or
2) having the media growbed as the only solids capturing bed and just pump from the sump to the in line wicking beds.
and/or
3) change the order so the media bed is first in line from the FT and run more water flow through that. ( on that note you have not drawn valves for the water inlets - you'll probably need those to control flow between beds.)

Oh ok. That makes sense.

My mistake, I meant to type Nitrates. My system has been running for two years now. Ammonia and Nitrites are 0, but Nitrates are probably around 180. Started with 12 red tilapia, but now have about 20+ Red Tilapia in the Fishtank (which will become the Sump in the diagram above.)


What timing cycle are you running? 15mins on 15mins off?



Think I will go with option 2. split the return from the pump, and have one goto the Fishtank, and one to the grow beds. Have to give it some thought.
Yes was planning on putting valves on the beds. Thanks again.

Don't forget to update your pics. Would love to see how it's looking now.

cycle is a bit odd as I'm using a timer with 16 on/offs in it so i run 45 ins on 45 mins off and have plenty of aeration in the tank.