Backyard Aquaponics
A place to discuss aquaponics

I spoke today with a chap called Ian Charles (I think) from Silverwater Native fish farm re Silver perch. He has good supplies and I will be getting 100 delivered on the 1st of Feb. About 40mm long he reckons- and weaned onto pellets. He also says he tends to have supplies of SP and Golden perch for extended periods
I have no association with Ian except as a customer so the details below are simply for BYAP members interest.
Silverwater Native Fish
Old Wagga Rd , Grong Grong, NSW 2652
p: (02) 6956 2122

Thanks Jim.... another for the list

Had a visitor to my fish tank today- a small , about 800mm, red bellied black snake.
I rescued him from the water and released him near our big dam and then realized that I had missed a photo opportunity.
My fish are now between 40mm and 90mm long and they would probably have been a nice snack for "joe blake" if he managed to catch any. As the fish are impossible to count I guess I will just have to wait and see if the numbers look reduced in any way.
As an aside the SP (and the tandanus cats) are looking good, although I lost about 25 SP in the first week or so. I am now feeding my homemade formula and they go bananas when the food is chucked in - big disparity in growth rates- the biggest are at least 5 or 6 times the body mass of the smallest.

We certainly dont miss seeing them joe blakes.

makes for a continuous supply over a longer period rather than do the lot in one go and freeze

Don't forget to post a few pics

Hi Jim,
I have just completed reading your thread and was wondering why we have not heard much from you over the past two months.

My late Father referred to Catfish as fresh water whiting. I caught my first Catfish boxing day 1949 at age eight in The Billabong near Jerilderie NSW. It was a four pound-er. It appears that most people think that they only grow to around four to six pounds. In 1836 one of the explorer Mitchell's men caught a cat in the Lachlan River weighing 20lbs plus.
Cats do not like muddy water and the carp in the rivers have had a big impact on our cats.
How are the cats going and how many SP's have you got now? Are the SP's in with the cats?
Janet the cats here in Aussie are a little dif to your cats in the US. I saw some in a pond in Dallas and our cats would not live in the very polluted water they seemed to be thriving in.

Alexmac... catfish.. indeed most species of fish, farmed in pond based aquaculture... are usually farmed in controlled algae bloomed ponds....

Was the pond a blue-green colour????

No Rupe,
the pond was not being used to grow fish. It was a pond in a park where I used to run each morning.
It was full of floating rubbish and the water looked bad. The cats were feeding around the sides and seemed happy enough. The pond would have been half an acre or so.
Our cats do like running water.
Alex

Sounds more like they were trying to get out of there ....

Alexmac,
My system, like all others, is going through various learning stages- even more than I expected.
The cats , and the SP which are in the same tank, are doing reasonably well but are growing fairly slowly and I am still not quite sure why.
At the moment the water temps are between 11 and 14 degrees which has reduced feeding drastically and naturally growth has slowed. I have also lost a couple of cats (3 or 4) in the last few weeks. Interestingly the cats are more active than the SP at current temps.
I do lots of water chemistry tests and Nitrogen compounds are right where they should be.
I am beginning to think that basically the weather here in Burra (near Canberra) is just too cold - certainly much colder than Perth, etc where the
Barra growth is so good. During the summer the maximum temp in the water was about 24 degrees. And then that was only for a month or so.
I would hate to have to put trout into the system but that might be the go next time.
I am currently in the final stages of construction of a heat exchange unit for the fish tank. It is based on an old but still good solar hot water
panel heater. More info and pictures when I get it going. I have a feeling that if the heater works it will probably take months to get the water up to a better temperature for fish growth BUT the insulation and bulk will keep the higher temps for cooler weather. Fingers crossed!!
Plant growth has been quite astonishing when the size of the fish is concerned but even here I am concerned that some plants look like they are deficient in some mineral or other- yellowed leaves etc. I have added Urea and chelated Iron some time ago and have just started adding crushed basalt in the hope that that will provide a better balance of micro nutrients.
If you are interested I have a blog with a bit more info on my progress so far.
http://wjastoys.blogspot.com/
PS my Dad used to catch catfish in the swamps and creeks around where we lived in the Riverina in the 50's and 60's. As I have mentioned before the taste of fried catfish on toast for breakfast is one of my most persistent and pleasant memories.

Hi Jim,
I have a stainless steel milk cooling unit much like a heat exchanger that I intend to run hot water through instead of cool water. Pump the water from the sump through the milk side of the unit heating up the grow GB's then back to the FT's.
The plan is to use all that nice gravel in the GB's as a heat sink.
The hot water pump is one that is used to even up both flow and heat in large houses ,motels hotels etc. it costs very little to run and can run for years without problems.
It may take some weeks to bring the water in the fish tanks up to a suitable temp and from that point it should be a simple matter to keep it at that level.
There is an old hot water service in the dairy which I am told works ok it has a copper tank. I intend using solar as soon as I have the time to construct the unit I have designed myself. If this unit works ok I will put full details onto the forum site.
Alex

It is about time I updated this thread with my experiences of the last 6 months or so.
Basically I think I have learned the hard way that the Canberra region is too cold for an unheated BYAP system.
As I mentioned in my last post the water temps in my fish tank were dropping and eventually a low of about 6 degrees was reached in early July and the temps stayed in the 6 to 8 degree range until late August. During this period I lost ALL my Tandanus cats and perhaps a quarter of my Silver perch. I did try and make a heater for the sysyem using an old solar hot water panel but I ran into problems with the heat exchange unit I felt I needed as the HWS panel was the usual copper unit. I'll not bore you all with how and why that plan failed- suffice to say the water was stayed too cold for the fish. I continued to do water chemistry tests and at no time do the numbers look damaging to the fish ie nil ammonia and nitrites and 20-40 nitrates. The fish refused normal pellets during the cold but did eat live Daphnia which I supplied almost every day.
I selected Tandanus and SP on the assumption that they could survive temps down to 2 degrees. This in fact may be possible but I suspect that it would be for fat, healthy adult or sub adult fish. Little tackers of less than 90mm simply can't survive these sorts of temps for extended periods.
In desperation I designed another , much simpler heater for the tank. Needless to say I should have observed the KISS principle but hindsight is usually 20:20. The water is simply pumped out of the fish tank with a small 12Volt bilge pump, through the 30 feet of 19mm black poly in the old HWS box (with previous internals removed) and then dropped straight back into the fish tank. The pump runs when a differential switch determines that the water in the heater is warmer than the tank water. The pump moves about 1200litres an hour and runs between 5 and 6 hours a day. It seems to raise the water about 1 degree for each pass through the heater. No where near as flash as the evacuated tubes one Rupe is creating but the principle works. I plan to insulate the box, the tubes etc for next winter. I also plan to run the unit over summer to get as much heat into the system (without cooking the fish) while I have the chance.
This unit has lifted the temps back up to a level (lows of 14 or 15 and highs of 18 or 20 degrees) where the fish are now feeding voraciously on the pellets and Daphnia.
I also put the main pump on a timer and turn it off between 8PM and 8AM each day as clearly the cold in the shed was chilling the growbeds which in turn were cooling the fish water .
I still believe that insulation of both fish tank and growbeds is essential in my part of the world.

I forgot to mention that the low temps in the GBs over winter almost completely stopped plant growth.
We did manage to get some paes to sort of grow and we have actually harvested a few pods in the last week or so.
My thinking is that even winter crops like brasicas(?) need some soil warmth and it seems logical to me that the dirt garden would take a lot longer to get really cold a few cm's below the surface??

Agree with the crop growth, and fish death causes.

Good to see your still trying, and that heater looks great

Jim, exactly the same experience. Though if you've seen my thread, mines outside and actually froze. Canberra winters are too cold to not heat. My plants didn't grow and my fish died.



Come spring and my water temps are 15-16 and chugging a long smoothly now.

I did the same KISS water heater as you did (on a much smaller scale), and found that it worked pretty well.



Also covering the top of the tank and covering the whole thing in greenhouse material (no photo) seemed to raise the temps quite a bit. I also wrapped my fish tank in bubble wrap, but I don't know what effect that had - I think my bathtubs act as big heat sinks and I lose a lot of heat from them. Next winter i think I will need to insulate them.