Saturday, May 4, 2013

A Post script

Michael looks a bit surprised at how easy that was
I haven't posted since late 2010 because the damage at the time due to heavy rain, coupled with the lack of growth of the fish pushed me to make the decision to close down the system.
And so we went fishing!! The wild eyed chap is our mate Michael and the cheezy chap is my next door neighbour Chris who is one of those lunatic trout fishermen.
Chris may have caught the biggest one
Not very sporting way to catch fish but good fun non the less.The fish were caught using the old method of worms on a hook. But then they went off the bite and so drastic measures were needed to catch them ie a BIG net. The big disruption due to the heavy rain occurred in December 2010 and we finally netted out the last of the fish in March 2011. (Or so I thought- more on that later - see the bottom of this post). About half were big enough to eat and the rest were still runts. The small ones we released into the big dam and with a bit of luck they are still there. I think we released about 50 or so into the dam.

An even less sporting way to catch fish

Unfortunately the flavour of the first ones we cooked was not great and so we have not eaten many of those which were big enough to kill and freeze. They are quite good in a fish curry but not so great when baked or fried.
A tiddler
The chooks however just love them- Di cooks a couple every now and then and just throws them in for the chooks who go bananas.

not much reward for a LOT of time and effort

The system was just left then as I had a million other things to do.
What a mess
Then in March 2012 we had another heavy rain event at home and the main tank was pushed even further out of the ground. I had at some earlier time pumped some of the water out but it still had a foot of so of water in it. You can see that it really was a mess.

 My biggest surprise at this time however was that at the time I spotted the snake below I also spotted fish in the tank. Clearly I had missed a couple when I did the big clean out in March 2011!!!!!
I will admit to being a bit slack and not doing anything about the fish at the time and I found one dead and floating in the tank not much later. Today I thought I had better do the right thing and so I pumped most of the remaining water out and climbed into the tank wearing waders and with the net I used last time. And I caught another fish which was about 200mm long. It was skinny but not diseased and seemed reasonably active. I said goodbye and floated it onto the big dam. While trying to catch this one I did catch a fish skull in the net so I can see where some of the survivors food has come from . And I can only assume that the fish ate algae and whatever critters were unlucky enough to fall into the tank. I know frogs get in occasionally and I suspect the occasional skink might fall in as well.

 A remarkable survival of almost 2 and a half years without supplementary feeding - tough little chaps Silver Perch.

And the snake?

 Hello- Joe Blake
Imagine my surprise when I just happened to look into the tank in late January this year to see that I had trapped a visitor. The polystyrene block had blown into the tank from one of the shelves in the shed. Yes -it is a healthy Eastern Brown Snake who seems to be saying to me that he would quite like to be somewhere else please. I rescued the snake and kept him in a box for a couple of weeks intending to use him as part of one of our Wildcare snake handling courses. As it happened the course was rained out and so the snake was released back into the wild the day after the course was cancelled.

I have not yet completely demolished the system in the shed but that will happen in the next couple of months as we need the storage space again.
The hydroponics tanks in the conservatory are still going and are a success now that I don't have to worry about keeping fish alive as well. We get a steady supply of greens, peas and chillies  which keeps Di happy.

Saturday, December 11, 2010

The end of the experiment

Some discussion first of the effect of the big rains we have had recently . Basically we have had a very wet spring and finally the drought is broken in our part of the woods.
The big dam had not been full for 10 years. However it has now been overflowing for more than a week and the huge rain of 2 days ago probably caused the water to be at least a foot over the spillway. This happened at night so I was unable , and unwilling, to go out and see how much water was running through the dam.
The picture of my Honda MUV and the road shows some of the evidence of the huge water flow at the time. The small 1000 litre tank on the side of the road was at the bottom of the gully and about 30 meters from where it is now sitting. And it is sitting just as I found in on the morning after the big rain.
We are counting ourselves very lucky as the rain did cause us some problems but they are minor compared to what happened to many others in eastern Australia at the time. The third picture shows the creek as it has been for a couple of days. It was clearly MUCH more destructive during the night in question. The section just down from the road crossing now has a gully which is at least a metre deeper that it was the day before.

And now to the aquaponics systems.
My reader will see that I have not posted to this site for almost 9 months and this may well be the last post .
Basically the systems have been only a moderate success and the workload is more than I can justify at this stage.
The main reason for the loss of enthusiasm is that in our climate the winters are too severe and the fish either die or simply stop eating during the colder months. Both of these naturally mean that the reward for the effort is rather small.
I have had ideas of building a super insulated, partly underground, greenhouse but they are on hold at this stage- simply too much work.
I have also had a fair bit of trouble trying to control white fly which really upset last years production in the big shed.
Actually notwithstanding the pest problems the vegie yield has been quite reasonable. The most successful plants have been peas and they keep cropping for ages provided they are harvested often.

However we have still not eaten any of the fish. The original silver perch are now about a foot long on average and the plan is still to catch and eat them.
The second lot of fish which were in the black tank in the conservatory have been caught and released into our big dam. They didn't grow well in the black tank. I am assuming this was because I was over cautious about feeding them. I had a few problems which I put down to an inadequate area for water filtration and so I tended to feed vary sparingly. When caught for release the fish were between 60 and 150mm long which is quite disappointing. And of the 200 initially put into the tank I caught about 100 for the dam.
With a bit of luck they will not have been washed out in the last week or so.
The black tank is now out of the conservatory and is finally ready to be used as a purging tank for the large silver perch.

The final nail in the coffin of the Aquaponics setup is evident in the picture of the main 4000 litre tank which is now well and truly out of the ground. Water running down the hill and behind the big shed has soaked into the ground and literally lifted the tank part way out of the ground. And it is unlikely to settle back into place as gravel has fallen down the side and presumably under the tank as well. Like all the other rain damage this happened a couple of days ago when we had about 80mm of rain overnight- on ground which was already well and truly soaked.

As you can imagine I have put a fair bit of time and effort as well as money into these aquaponics systems and I was keen to get some further use from the bits.
And so I am now using the smaller systems as hydroponics grow beds. I had planned to do the same with the big system but a complete rethink will be needed there as a result of the tank being out of place. The system is still sort of working but I am not sure that the big tank is not cracked as the water level seems unusually low. And the fine tuning for the float switches is all out of whack.
To date the small systems are working very well. Di has been harvesting lettuce from the first bed for some time.
Straight hydroponics is a bit of a cop out as I have to buy chemicals to make up the solutions but it is a lot less work.
I decided to change the gravel in one of the units as I am convinced that the original gravel I used has a lot of calcium buffering and blue metal is more common and accepted.
To date the first tank converted looks terrific and it has the original gravel but I have to keep adding acid to get the pH down below 7.
The second tank has the blue metal and so far the pH has not needed adjusting.
With lots of sun and warmer weather now here we are looking forward to fresh vegies for the summer. A smaller grow area but it does look promising so far.

Friday, February 12, 2010


The second system, the big black one, suffered a major attack of a pest shown at various stages in the first 3 pictures. It is a little green grub, max size about 8 -10 mm long. Pupates ala the white cocoon and then hatches into a small moth which is also about 8mm long- rather boring appearence grey/brown colouration.

I have killed all the moths so can't take a pic for this post.
If I tried I could find a lot of the grubs and pick them off and then feed them to the fish. However I was not winning.

In a desperate effort to get this problem under control I decided to make some rhubarb leaf spray. A web search provided a number of different ways to make rhubarb spray . There was significant variation in the methods . However I made some but in my enthusiasm I have almost certainly killed off the bio filter in the grow bed. I did manage to kill most of the grubs and the moths but not before creating a new problem. You can see the current state of the growbed in this picture. A series of water tests have shown consistantly high ammonia readings which are bad news for the fish. We have been doing big (30-50%) water changes a couple of times a week recently. Might add the water is not wasted- it goes onto Di's pot plants which seem to be thriving on it.

It's not all bad news. The new GBs are doing well as shown by the last pictures. These were supplied with water from the main fish tank and are topped up daily with 5 or 10 litres of fishy water to ensure a supply of nutrients for the veggies. I have recently moved half a dozen or so of the Silver perch from the black fish tank into one of these new 250 litre tanks- they hide all the time and don't feed anywhere nearly as enthusiastically as the fish in the main tank.
The main plants in the new GBs are Vietnamese mint and a Habenaro Chilli as mentioned before. These are really too hot to eat for us but we have some slightly crazy friends who accept what we unload onto them when they see the plant.
As before the seeds for these new plantings were simply placed straight into the gravel. We only use seedlings when Di sees something she really wants in one of the many trips to the local nurseries. The habenaro chill was one such seedling as our attempts to grow plants from last years chillies were not successful.

Friday, December 18, 2009

Main system

I should have mentioned in the earlier post that I have got the heaters running in the 4000 litre system in the big shed and the water has come up to about 25 degrees. This is costing about 10 Kwhs of electricity as expected but we have lots of spare and so it doesn't really cost anything extra. Clearly that is a nonsense as the system upgrade cost a bomb but I wanted to upgrade our power anyway and I got a 50% government grant to do so. Still nice to be able to do this sort of thing on solar power.
At this temp the fish are feeding like crazy so I will have to bit the bullet soon and try and catch some for eating.
My duckweed pond is also going very well. Lemna this time and not azolla. The fish eat about a cupful each night. I don't ever see them eating it as they are too timid but is it gone in the morning.

Another system

As you can see the plant growth in the second system is quite luxurious at the moment. This is our salad vegetables plot and at the moment we are clearly not eating enough bushes. The fish are eating very actively and I have to restrict their food intake as the GB is not really big enough for 175 fish which are up to 80mm long.

I have now finally got the third system up and running. This is supposed to be the large fish purging system but we have still not caught any of the eating size fish. I have cycled the tank, with nitrogen rich water from the black tank system, and it is now stable with a low or nil ammonia level.
This was the original planned second system but the bits didn't arrive in time and so I built the black system shown on previous posts and in the first pic of this post..

This new system has another variation on the fill and drain mechanism. I am using a bell syphon to drain the grow bed instead of the float switch and/or timer mechanisms of the previous systems.
I decided to try bell syphons because I have had problems with the other systems as I have outlined earlier.
A bell syphon is a simple device which basically allows filling to a pre set level and then an almost complete empty of the grow bed back to the fish tank. The pumps run continuously. The full flood/drain cycle takes about 14 minutes.
I tried using a single 6 watt pump but it can't fill the GB fast enough to trigger the syphon so I am running 2 of the little pumps. I bought them very cheaply on eBay some time ago and have been looking for a use ever since. The top of the bell syphon is visible in the last pic.
This growbed is being used as a part herb garden and part seedling production area. Di has already planted out the pumpkins which sprouted in the gravel.
It is really easy to start seedlings in the aquaponics gravel. Just scrape a bit of a trench and sprinkle in a few seeds and wait. Provided the weather is warm enough you get plants within a week or so. MUCH easier than the seedling mix which has to be kept moist and the beds covered etc with the old fashioned way. And no need to transplant if the initial seeding was done in a sort of even way.

Wednesday, November 18, 2009

A long overdue update

The last 6 months or so have been very busy for me as we have been in the process or upgrading our power supply big time. Many difficulties along the way with supply of bits. Plus the usual 1001 other jobs which need doing at the farm.
The new panels are above Phil and Ron. This picture shows an unusual weather event on 10th of October this year. Quite heavy snow for about an hour.
We have had a LOT of help from Ron Tito to accomplish this change. Actually Ron has been the driving force and without his advice and help the system upgrade wouldn't have happened.

And what has this got to do with Aquaponics you might ask?

Well..... it means lots of extra power to help me overcome some of the problems I have had with the Aquaponics systems.

The major problems I have encountered with the fish have been as simple as low water temperatures. Previous posts have detailed my efforts to get a sort of water heater going for the big fish tank. And to some degree (pun unintended) I have had some success. The lowest temperature in the big tank this winter was about 8 degrees and then only for a week or so. Last year it went down below 7 degrees and we had a couple of months below 10 degrees- and that killed all the catfish and most of the silver perch.
So the heaters worked vaguely as intended. I had to make a third one and I struggled with failing thermostatic control and cheap and nasty Rule bilge pumps but at least I haven't lost any of the fish. However another of the Rule pumps failed the other day and I decided to give up on that part of the heating system.
I have taken delivery today of 3 x 300 Watt Eheim aquarium heaters which I plan to put into the main tank in the very near future. These should be best quality if Eheim is as good as I remember from my Scullin aquarium days.
My crude calculations point to a 2 degree water temp increase for the input of 10 KwH of power. This was unthinkable before our power upgrade but we now have power to burn literally.
We have so much overcapacity now that the inverters are regulating power into the batteries as early as 10AM on most days. And we have a new wind turbine as well and wind turbines MUST have a load dump available so the fish tank will probably end up getting power from Jock as well.
Old wind turbine was Toby- a Swiss unit and Toblerone is Swiss- get it? Well Jock is a Proven wind turbine made in Scotland- so called Jock.

The other pics are of the plant growth at the moment. As you can see a bit of heat and things finally begin to grow again. We experimented with all sorts of supposedly winter plantings this year but the only things which can really cope are peas and silver beet. And the peas do really well so next winter we will probably plant all the beds to various types of them. The silver beet will stay as well as it just keeps powering on. These are now 2 year old plants which have provided a lot of chook food in that time.
We have let the lettuce go to seed just to see what happens. They grow too slowly to be much good to eat at this time of year and so the chooks benefit. They really love leggy lettuce.

And what of the big fish?
As usual I am unable to get good pictures and so you will have to believe me when I say that the biggest are probably more than 300mm long and ready to eat. I think I will try and catch them on a barbless hook. Only problem is I don't want to catch or hurt the smaller ones which are still only about 150mm long. There has been a huge variation in growth rates.

And what of the smaller system in the conservatory?
The higher minimums in this tank meant that the fish survived the winter but they haven't grown much. Now probably about 70-80mm long.
I think part of the limited growth we have experienced is due to my reluctance to feed as much as they might prefer. It has always been my philosophy that it is much better to underfeed than overfeed. Overfeeding is the quickest way to kill fish if any part of the system stumbles.

And a final pic of a fish which we found floating in the big dam in July of this year. It is a Murray Cod- about 600mm long and probably more than 10 years old. My nephew Ged gave me some mixed fish fingerlings quite a long time ago and I assume it was one of those. I was quite surprised to see this fish as we thought all the fish in the dam had died a couple of years ago when we had a big runoff event which made the water VERY muddy and probably suffocated the remaining fish.

Wednesday, April 1, 2009

New Fingerlings

As the fish in the main system are almost big enough to eat I decided I had to have a batch of new fish ready to put in when the big ones are gone. And as Silver Perch are really only available about this time of year I ordered 200 from Silverwater as before. I doubt they would survive with the larger fish so I had to build a new system for the little ones.
I have ordered some fibreglass tanks from Murray Hallam in Queensland but he is rather slow to respond to orders so I decided I needed to build a temporary system.

So I cut up one of the 1000 litre IBC's I had bought a year or so ago to try and water shrubs we had planted out on the farm. Not enough spare water to use them at the moment for the intended purpose anyway.
I took a saw to both the steel frame and the plastic container to produce both the fish tank of about 650 litres and the grow bed of about 350 litres from the one IBC. The grow bed needs to be about 300mm deep and that was the reason for the proportions of the split. A system with this size growbed will only support a fairly small fish load but that is the plan anyway- the fish will go to the main system long before the growbed is unable to cope with the nitrogen load.

Then I welded up a support frame for the growbed which enables it to sit over the fishtank. I also added a pine platform over the steel frame and then several layers of expanded polystyrene foam- mainly to support the odd shape of the old top of the IBC which is now the base of the growbed. I glued the screwoff lid on with silastic and cut 2 drain holes to ensure complete drainage.The growbed sits directly over the fishtank and the drains drop straight into the fish water with drain which are exactly the same as those in the big system.

I didn't mention that I also decided it had to be in the conservatory to reduce the likelihood of low temps over winter which I already know are lethal to the fish. In the time we have lived at the farm the lowest temp we have recorded in the conservatory has been about +7 degrees (when it was -7 outside) and the water in the fishtank should not go anywhere near that low point just overnight. And so I shouldn't have to build another solar heater for this setup.

After setting the system up in the front corner of the conservatory I started washing gravel. With the first system I didn't wash the gravel as it was much too big a job and we couldn't afford the water. This time I didn't want muddy water for a month and I thought it wouldn't be too big a job. Another underestimation. It took me about 3 or 4 hours to wash 300 litres of gravel. Still I did it on the lawn so the water wasn't wasted- that is now the only part of the lawn that doesn't look like straw. I also stole about 50 or 60 litres of gravel from the main system in the belief that that would get the nitrogen cycle started sooner. As it turns out I have an Ammonia level much higher than expected at the moment, in the fingerling system, so perhaps that didn't work as well as it should have.

The plan for this growbed is that it will be herb garden and Di had bought the starter plants even before I had washed the gravel- talk about pushy!!

I am using a really neat electronic timer on this system which is currently set up to run for 6 minutes 15 seconds on and 50 minutes off. Both of these times are adjustable to the second and the big benefit is that I don't have to keep the water topped up as carefully to ensure proper flooding of the growbed.
The pump is a pond pump which can move 1000 litres an hour to the head I have on this system and it only draws about 14 watts so the total power usage is very low- much less than the big system which has a pump which draws about 400 watts for 9 minutes in the hour.
The fish arrived last Thursday and look terrific- about 40-50mm long and so far I don't think I have lost a single one which is quite a surprise. And they are hungry and come to the surface to eat unlike their big brothers in the big shed. I think this is because the growbed almost completely shades the fish tank- ie no sun on the water.
I am logging temperatures and water chemistry for this system as well so I will be able to compare the performance of the two systems to some degree.