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.

It's HOT

Today is not actually hot , in fact it is quite cool outside- about 17 degrees.
However it has been very hot this month in most of Eastern Australia.
The maximum here at the farm reached 36 degrees on 6th, 7th and 37 degrees on the 8th of Feb 09.
Fortunately we didn't reach 40 or 41 as they did in Canberra.It is always a little cooler here than in Canberra as we are at about 850 metres above sea level which is about 200 metres higher than Canberra.
The water in the fish tanks got up to a maximum of 28.7 on the 8th. Fish very active but it is at the top of their preferred temperature range.
And so I decided to turn off my little water heater as I didn't want to cook the fish just yet.
Unfortunately that turned out to be a mistake as you can see from the picture.
This is the 19mm black poly from the high point of the unit which was the heat collector for the pumped water from the fish tank.
I assume that the line didn't drain very well and the remaining water must have boiled in the tube creating steam and pressure which caused the blowout.
So I have had to make a third version of the heater. This one is basically the same as the last one.
I am getting faster at the manufacture but would prefer not to have to do it again. I think I will have to cover the whole unit with shade cloth if I need to turn it off due to higher ambient temps again.

The temperatures here have now dropped to the point where we have run the cooking stove at night- both to cook on and to heat our hot water in the house. Outside minimum last night was 6 degrees which is a huge change from the 23 degree minimum of the 8th.
And the fish tank has seen lows in the 15 to 16 degree range while the heater was broken. At these temps the fish are much less interested in food than they are at 25 to 27 degrees. There is no doubt in my mind that the heater is essential even at this time of year- even if just as a standby unit during the heatwave times.

My chillies are doing very well and are more than just decorative. The long skinny red ones , called Cayeene(?) are very prolific and Di has been using some in cooking. The label on the punnet said hot. And that is spot on. Only need one for a stir fry. According to Wikipedia it is hot:-
Heat: Hot (SR: 30,000-50,000)
It will be very interesting when we try the Habanero's which the label calls very hot. Considerable caution will be needed I think.
Wikipedia says of this type:-
Heat: Exceptionally Hot (SR: 100,000-350,000).
Habaneros thrive in hot weather. As with all peppers, the habanero does well in an area with good morning sun and in soil with an acidity level around 5-6 pH. The habanero should be watered only when dry. Overly moist soil and roots will produce bitter-tasting peppers.
I reckon I am doing most things wrong here- constant flushing with water, PH at 7.8. Looks like bitter peppers coming up. Will report on taste later. This assumes that enough can be consumed to give a taste other than fire!

The black pearls are also described as hot so I think we have good , if somewhat cautious, eating ahead. Interestingly some of the black pearls are bright red and some are black almost from the start while others start off green and gradually go black. The roundish ones in the 3rd picture are the black pearls. They have lovely purple flowers most of the time.
All the chillies were really put in because I couldn't resist the visual attraction of the plants.

We have had a bit of insect damage to some plants to date. The white cabbage moth is seen in the shed from time to time and is clear they are laying eggs. I don't have a picture of the moth grubs which are being a bit of a pest by making a feast of the asian greens. Mostly I don't have pictures because whenever I see one I feed it to the fish. And very much appreciated they are too.

We have also had something decimate one of the lettuce crops. It happened between my visits to the shed so I suspect it might have been grasshoppers. That is a guess as I didn't see any beasties. The affected plants are coming back so it is no big deal.

Fish finally growing

It is now the 19th of January 2009 and we have only had 2mm of rain for the whole month. Not surprisingly everything is looking very dry. Now 8 years of drought and little sign of improvement.
I am again very aware that this aquaponics thing has to be one of the answers to the water shortage problem. We had a new water tank installed today, up the hill behing the house, and this brings our potential fresh water storage to 63000 gallons or 285000 litres . At the moment we are at about 50% of total capacity so we are now hoping it rains soon or the lawn and gardens will really start to suffer. We have been unable to draw from the big dam for several years now.

I have to add an extra 50 litres of water a day to the aquaponics fish tank, at this time of year, to make up for evaporation. This water comes from the 22,000 litre tank attached to the big shed which has the AQ setup. I have been carefully measuring this top up water for a year and have added almost 8000 litres in that time- slightly less than I had guessed would be needed and not bad considering the fishtank holds 4000 litres.

Had a problem with my little solar water heater setup for this system. I have no idea how but the poly pipe blocked up completely and I spent hours trying to clear the blockage. Used the big pump and lots of compressed air but I was unable to budge the blockage. I could even see where the pipe was distended. Unfortunately I had done too good a job of sealing the glass top to the heater and I can't work out how to lift the quite thin glass without breaking it.
So I had to make a new heater. I had actually planned on some improvements anyway so It wasn't quite the disaster it might seem. The new one looks a lot like the old but has a layer of expanded polystyrene foam under the absorber plate this time. I used the old plate from the original HWS heater- it is aluminium and painted black. I had a few problems with the poly pipe kinking but eventually I got it to sit properly. I have covered the whole thing with a clear, very heavy duty, PVC sheet about 1 mm thick. I also added a little filter to the line after the pump. This is one of the poly ones usually put in irrigation lines to stop drippers from blocking. It is too fine for the job and requires cleaning most days so I will experiment with various alternatives. It may not really be essential as I can open the heater and simply cut and rejoin the pipe if a blockage happens again.
As far as I can tell this new heater is giving me an extra 3 or 4 degrees in the water tank each day and daily minimums are now up to the low 20s and maximums have reached 27 or 28 degrees on hot days when it have been up to 35 degrees in the shed.

This increased water temperature is what I really need for the fish and they are now growing quite rapidly. They are eating voraciously. Mostly pellets with the occasional treat of worms. The pink things in the picture are the worms from one of my worm farms.
These are the same worms I introduced to the grow beds. Somewhat surprisingly they survive and breed in the GBs despite complete flooding of the beds every hour.

The biggest fish must be close to 200mm long by now while the smallest are probably close to 90mm. The big ones could be eaten now but I feel it would be a waste while they are growing so fast. Perhaps big fat fish dinner for Easter?? I will have to set up a purging tank before then and also work out how to catch them without damage to the others.

The bushes are growing well. My chillies look great and the tat soi and pak choi are doing the right thing. We have had a lot of spinach and sugar peas. Actually the spinach goes to the chooks.
I am now quite sure that the shed doesn't get enough light but we are learning the plants which can benefit from the current setup. For example lettuce grows slowly and really isn't worth the bother as it becomes bitter when grown so slowly. Still that's another "failure" that the chooks appreciate. It's all about finding the right balance.

Perhaps I am winning.

I will begin this post with another gratuitous picture.
The deer in this shot have been transient in this area for several years. We have seen one or two on an infrequent basis. However in the last month or so they seem to have taken up residence. And in somewhat larger numbers. I first saw, and photographed, this group of four on 27th of October of this year at 7.30 in the morning. And now they have started to appear all over the place. We now seem to have a group of five or six who can often be seen down near our bore. And the resident mob don't include the two bucks seen in this picture. And I had to dodge another one when on the way into town a couple of weeks ago- in the mid morning. That animal was about 8 or 9 clicks from here on the road near Little Burra Road. So far I haven't noticed any roadkill deer but it is probably only a matter of time.
I suppose we should be attempting to control deer as they are feral but I can't bring myself to do so. Bit too cute and cuddly. Also it would be a waste not to eat them if shot and I don't really fancy the whole business.

And so back to the aquaponics.
In the last month or so things seem to have finally begun to show the sort of growth in both plants and fish that I have always thought were possible.
My little heater for the fish water is getting the temperatures up into the low to mid 20s and this is clearly better for the fish. They are eating lots of pellets and on one or two occasions were so hungry that they even came to the surface for food. This is unusual with my Silver Perch which would have to be the most "chicken" fish I could have picked. Some guests don't believe that I have fish as they have not seen them- even when standing right next to the tank!
I have again tried and failed to get adequate pictures- the fish are too nervous and the light levels are too low. Even my new "you beaut" digital SLR camera can't catch them. However just to prove that they are there I have included a fairly poor shot taken a week or so ago. The biggest are probably now close to 140mm in length- basically about a hands length long and perhaps half a hand wide. They are quite deep in the body. When viewed from above they look to be perhaps 25mm or so "fat". The smallest are still only 60mm or so long- looks like we will have a good long period of harvest. The white stuff to the left of the picture is out of focus azolla.

The vegies in the grow beds are growing well- we have had lots of peas and lettuce so far this month. The asian greens are again doing well as is the spinach. I have also planted some chillies for colour. Went shopping to a garden centre the other day and I couldn't resist them.

I am convinced that my last major problem with the whole setup is not enough light. The plants grow but they struggle with , at best, only 4 or 5 hours a day of full sun. I don't want to put more polycarbonate onto the roof- it is a shed after all and sun in not good for all the other things stored in there. Solution may be to simply grow plants which tolerate lower light.
The last picture shows various lettuces and some beans and peas which are doing well. This is the third lot of peas Di has planted. Actually it is the fourth but the third turned out to be sweet peas which were incorrectly labelled.

The outside azolla production is going very well. I am no longer harvesting and drying for the fish as I have a 10 litre bucket of dried leaf in stock. However the new chooks go bananas over fresh azolla. So they get a small bucketfull most days. All from the 1200 litre stock trough. The growth in the blue barrels is disappointing and I will have to work out how to improve that. I suspect that the water gets too hot as it is shallow and in full sun- perhaps a little shade cloth cover might be the go.

We had about 7mm of rain last night but it is still very much drought here and again I am reminded of the need to be conservative with our water. And so aquaponics must be one of the answers.

Warmer weather

Finally some good news on the fish front!
The water temps are now in the 16-17 minimum to 19-21 maximum ranges and as a result the fish are feeding voraciously.
I was worried that a diet of live food over winter might have spoiled the little fishie palates to the point that they would not eat the pellets which are the main food source.
However the first offering of pellets was eagerly accepted- as was the first seasons chopped earthworms and my home made formula (liver, eggs, prawns and azzolla).

I reckon I only have about 40 or 50 Silver Perch left after the winter. And I can't see any of the catfish so I suspect they all died. $300 down the drain so to speak.
I don't yet have a good picture of the fish as they are very reclusive most of the time. However I have indulged myself with a new camera which promises(?) more manual focus and so if I get the time of day right and there is light in the right part of the tank , I should be able to get some shots. The biggest of the fish are now perhaps 100 to 110mm long and looking good!! Given that they are Survivors it is almost unfair to consider eating them - but I think we will manage to do so- perhaps even before next winter.
Actually on a slightly gross note- the dogs discovered that I had thrown the dead fish out onto the ground in front of the shed as I scooped them out of the water. And so they ate all they could find.
Even after I realized this was happening and started burying the bodies the dogs dug them up if I was not watching. I guess it is all just good use of the protein.

The warmer weather has also restarted the growth of plants. The peas Di planted in June of this year have finally taken off and we are now picking lovely fresh sugar snaps. Some of these even make it to the kitchen for cooking.
The top 2 pictures show the attempts made by the peas to escape the shed. Some are perhaps 6 or 7 feet high.

The coriander visible in one of the beds , in the bottom picture, is entirely self sown. We left the first lot of plants to go to seed and clearly the seed was dropped all over 2 of the grow beds. This really bolted last year and I doubt if we will leave it in the growbeds for as long this time as we will want the space for all the seedlings which are now coming up.

Di is really the gardener so I am unsure what is planned for this year. However planted seeds so far, and this is really just in the last 2 weeks, include several varieties of spinach, several types of tomatoes, various asian vegetables and other assorted bushes.
We put some spinach seedlings in during June as well and they did absolutely nothing until the last 2 weeks. In truth they didn't do nothing- most of them keeled over. However 3 or 4 survived and now thay seem to be away.

In general I feel that I have proved the concept of aquaponics as viable in this area with one major proviso- I MUST find a way of keeping the winter temperatures above the deadly lows of this winter.
I am reasonably sure that an improved version of the current heater will be worth the effort. I plan to add more insulation, longer length of poly pipe in the box, black paint on the inside of the box etc etc.
I am however also again planning a heavily insulated, partially buried glass house. Needless to say the amount of effort needed to build such a building just might scare me off- but I doubt it!!

Water heating update

Just a quick note to record the apparent success of my little heater for the fish water.
My last post detailed the construction of a very simple black polytube heater which seems to be doing the job!!!
After about 2 weeks of operation it looks like the daily addition of just 1 degree of extra heat from the unit has raised the daily minimum temps , in the fish tank, from a low of 6 or 7 to a low of almost 10 degrees now. Still not warm but I think I am finally winning.
This new heat is a bit late for all those poor little catfish but next winter things will be better!!
Yesterday the minimum was 9.6 degrees- but it was a very cold day- it actually snowed quite heavily for about 15 minutes!! At the time Di and I were working in the chook yard making a new house for the new silkies- but that is another story.

I have also added a timer switch to the big pump setup so that the water is only pumped to the growbeds between 8AM and 8PM. The reasoning here is that the growbeds cool down during the night and so will tend to chill the water passing through them.

I have also got the differential switch working and so I don't have to go down twice a day to connect the 12V pump running the water to the heater.
Needless to say all is not quite a bed of roses- the pump draws more power than one 20watt solar panel can comfortably supply and so I have added a second 20watt PV panel.
This problem should be fixed soon as I have a mini maximizer kit which I will build and install when we get back from our little holiday to Hong Kong. This kit adjusts the voltage from the panels to enable a much more efficient conversion of the power from the panel to the load.

Winter Woes

A totally gratuitous image to start this post- this was the view I had when I wandered over to the big shed this morning to check on the fish. The local kangaroos are almost tame- certainly not much bothered by us- or by the dogs provided we keep the dogs close to us.



The period since my last post have been a series of learning experiences- most of them not good.
As we are still in winter the temperatures are still low- both outside, in the shed, and much more significantly, in the fish tank water.
My reasoning for putting the fish tank in an insulated hole in the ground were based on the assumption that the water temperature would be more stable. This has been the case. I also thought that the lowest water temps would be somewhat higher than I have actually measured.
I have been recording all sorts of details including maximum and minimum temperatures in both the shed and the fish tank water.
To date the lowest room temp over the last two months or so has been just above freezing. Night time temps have often been below 3 degrees C in the shed. Daytime temps have been as high as 17 or 18 degrees. And the daily fluctuation has been as much as 15 degrees or so.
At the same time the lowest water temps have been in the 6 to 7 degrees C range with a daily variation of less than 2 degrees. So as far as variation is concerned the buried tank works.
However the stability is a bit of a two edged sword- the tank doesn't heat up much without help from me.
At the start of this adventure I chose Tandanus tandanus and Bidyanus bidyanus species as the literature suggests that they will both survive temperatures as low as 2 degrees C. Perhaps well fed adults will but little fry clearly will not.

I think I have lost ALL of the Tandanus and perhaps another 10 or 15 of the Silver perch.

The highest numbers of deaths almost always follow the coldest days.

On a positive note the fish are still eating some Daphnia which fortunately is in good supply - they refuse all other non live food. They even reject chopped earthworms which were a favorite in warmer times.

I have even contemplated growing trout next time- however that probably won't happen for another reason- the lower temps are not only bad for the fish but also for the bacteria which are responsible for changing the fish waste into plant food.

The growth of the current plants has almost stopped. I doubt if this is due to a lack of nutrients as much as simply a medium which is too cold. I reckon that in a dirt garden the soil can soak up a bit of heat from the sun and this help the plants. My plants are constantly bathed in coldish water. Perhaps I need to do some more experiments in this area.
Having said the above- all is not doom and gloom- the peas are sort of growing. And the tat soi has a bunch of pretty flowers. The tomatoes have all been removed.

And so I tried to adapt an old hot water solar panel heater to heat the water. As the solar panel has copper pipes and connections and copper is known to be toxic to fish I decided to make a heat exchange unit to transfer heat to the fish tank water without allowing the water heated in the solar panel to come into direct contact with the water in the fish tank. As the water in the heater panel would be subject to freezing I also used a glycol solution in the system. Glycol is also toxic to fish but I reasoned that the circulating water would not come in contact with the fish water so this would be OK. I made a big loop of plastic pipe to immerse in the fish tank and tried to pump the antifreeze solution around the system. Short answer - it didn't work- too much trouble getting the air out of the system etc. And the heat transfer ability of the plastic pipe is terrible. (Can't use copper for toxicity problem mentioned above, couldn't find aluminium pipe and stainless steel tube is VERY expensive).
So I have now made a much simpler heater for the water.
Basically it is 30 meters of 19mm polypipe inside the box that had held the first solar hot water heater panel. The water is simply pumped out of the fish tank through this polypipe and back into the fish tank. Crude measurements of water temp suggest that on a good sunny day, even at this time of year, I am getting a 1 degree increase in water temp during this pass through the unit. The pump I am using is a 12volt bilge pump rated at 350 litres per hour. The power for the pump is a 20Watt solar panel , a Solarex regulator and a couple of 20Ah sealed lead acid batteries. I am now trying to fix the differential heat switch which I am using in an effort to automate the process of pump on and off switching.
My current thinking is that I might be able to keep this heater going in the summer to get temperatures which should cause explosive fish growth. And perhaps even prevent the lows of this winter by "loading" up the tank and it's surrounds during the summer. Time will tell if this logic is sound or not.

To add to the problems I am having I have discovered, in the last couple of days, that the float switch which turns the big pump on and off has stopped working properly. Actually it is worse than that - it works intermittently. With a bit of luck a little adjustment to the weights and levels of the cables will fix this problem.