Backyard Aquaponics
A place to discuss aquaponics

Will soon start my fists system. Am going very small as an experiment to decide whether I give the real thing a go.

I have a round polly tank - 115cm diameter and 45cm deep. I guess I will put about 400 litres in it, filling to a depth of about 40cm.

I want to put silver perch in it. How many should I start with and will I then need to cull as they get bigger. I would rather not do this for obvious reasons (want to get them to good eating size before killing), so would prefer to add more grow bed as they get bigger - is this sound thinking?

Any guidance appreciated, including how much grow bed to start with while the fish are still small (obviously the 2:1 bed to tank ratio would not be appropriate at the start).

Thanks.

If you were getting small fingerling of say around 50mm I would probably think of putting at least 20 into 400 litres. There will probably be a few deaths over time, so maybe 25.

If you had a grow bed ratio of only 1:1 you could support about 2-3kg of fish per 100 litres. 20 fish grown to plate size of around 500g makes 10kg.
You could start with a growbed of around 200litres (a blue barrel), giving you a ratio of 0.5:1 while they are small, then double it later as the fish are growing....

Temporary holding / growing tanks ..

Well Armadale city council have old wheelie bins for free ... 240 Litres a good scrub, disinfect, and so long as you pick ones with no splits in the bottom, they can provide a good temp solution. (If you want old bins from Armadale - I can get you a phone no. no problemo!)

I simply added a 300 W heater, bucket filter (air powered) - containing washed shell grit, washed pea gravel and coarse washed sand and a real cheap submersible pump with a sponge filter attached. When it starts to get really cold, I wil reduce the airflow a little and wrap some bubble wrap around the tank.

Get some pics here:-

www.communisat.com/johnnie/FHT.doc

How many fish such as silver perch or tilapia should I stock these with if I want to grow then for meat? 15? 20?

Thanks.

Oh .. I forgot .. where can I get 40 tiny baby siver perch from (free if possible - they are for a school science project at the school where I teach)?

and would I need to use a heater with them?

Do they breed easy?

Many thanks

Johnnie

Johnnie,

I got mine from a place in queensland, they don't generally sell direct to the public, but i'm sure a school qualifies You may want to post a message in the forum (buy/sell/trade section) to see if anyone else wants some and is willing to share the shipping cost as i don't think they will supply less than 100.

http://www.ausyfish.com/perch_fingerling_prices.htm

$1 each (excluding freight)

let me know how you go, i might even be in it if its a little later.

Oh, by the way, they won't breed in captivity unless they are injected with hormones, and i'm fairly sure you will have trouble getting your hands on Tilapia as i think they are a decleared species in australia due to their prolific breeding

Cheers

Steve

Thanks mate ..

Tilapia .. not declared in WA! But the dept of fisheries etc. etc. are aware .. and I am in contact with our local Fisheries rep .. to see if I am allowed to do what I want!

I am very wary of the probs and no way would I let one of these amazing fish loose into the environment! (They are so educational!)

I worked with these fish on an AID program .. the fish equivalent of cane toads ... in the UK in the 80's as part of and AID programme!

These guys taste lovely! and for my existing batch (which I have already!) .. the only way they are leaving the tank is via the barbie! ..

YUM!

I eventually want to raise some local species .. for ornamental or food purposes .. just playing around ... but if I can et the kids interested in learning about fosh , that would be amazing!

One set of this batch is being raised on pig food ... I am hoping I can raise another batch on rabbit poop! ..

If I can do this .. and report it properly somehow , then my students may learn something about having a good go at learning some of the ideas regards sustainable farming, backyard aquaculture and maybe aquaponics on a shoestring .. and maybe how this may help people in countries where water and animal protien are real hard to come by!

I am just learning .. (bottom rung on the ladder!) and I thank you for your assistance .. nothing like listening to people who can teach me ... thank you so much!

Oh .. I got a few of them Mosabbiques ..and a few Green chromides ..too!

I think I would like to try fostering some real rare , but easy to keep africans ..

I saw electric yellow cichlids .. $ 12.50 for a specimen less than 2 cm.

I reckon I could grow over a hundred of these in my 250 L tanks .. if they get too big ... like goldfish .. you limit your market! People want "handle-able" babies!

(The yellows I saw were very bright coloured though .. best I seen!)

Bugger!

I registered .. but my name etc. isn't happening yet ..

Doh ..

I will master this!

Lets see if this works!

Sorry if I am wasting anyones time!


Whoooo HOOOO

Done it!

The above guest posts are mine .. (Several of them at least!)

I had a load of probs getting registration to work .. but eventually .. it has happened ..... what a great site ...

Hey johnnie,

The work your doing sounds fantastic, kids can gain so much from aquaponics. Your farm school sounds interesting, perhaps you could tell us a little about it on the General Banter section...?

So your planning on breeding and growing ornamentals for sale? This can be a great way to make some money when you look at the price they charge, even breeding goldfish can be a winner, and they're providing the nutrients for your veg at the same time...

You got it!



These year 8 kids raised 200 $ in 5 weeks from selling the odd veggie ..

imagine if they were selling young goldfish, koi or other ornamental fish ...

So ...

if anyone one got some nice easy care breeding stock for free,, my excellent year 8 Students will look after them ... and make you proud ...

Offers of any surplus fingerlings .. quality goldfish or Koi , Good quality bright Cichlids maybe, anything freshater that grows quick and does not mind a little variation (small variations) in water quality from time to time..

I guess robust fish that are "pretty" and saleable and grow quick .. ...

That would turn some of the kids on!

Oh ..

I digressed .. sorry!

how many meat fish for rapid growth in a wheelie bin (240 L) .. silver perch or tilapia ... males I think are best .


15 - 20 ?

That number is probably even pushing it.

may be fine to start with with supplemental airation, but when they grow to 750grams each? Probably not.

Joel would have the best idea

Steve

Argh! We have an armadale in victoria.......assumed u were from this side.........i guess the "buy in" for the perch is out for me

Steve

Hee Hee ...

I am a westie ...

I think they have an Armadale in Scotland too!