Backyard Aquaponics
A place to discuss aquaponics

I cant say i wouldnt do the same I dont understand what patience means as i got 20 yabbies and 25 silvers last sunday even without the stand pipe plumbed up for the GB

With the stock densities i would probably ease in the fish so not to overload the system. I would probably go with 2kg/100L then as tests show me that plants are taking all the nutrients up then increase that. But then again im a noob myself so probably wait till Rupert or one of the other guys answer your question

netab what are your volumes of tanks / bb's again?? im afraid i got lost in all the looooooooooong thread you have developed and also how many yabbies do you have??

i would suggest stocking lighlty for the fisrt lot of fish (6 months) to let the system mature and develop its own little ecosystem, then add all the fish you can

my system took about 3 months so fully cycle till it was stable (ph included) and i rekon only now (8 months) i can start pushing the fish stocking limit unfortunately its going to be pulled apart soon though

Freoboy its not THAT long yet... only just 17 little pages Ill be pretty impressed if it ever gets over 100 tho

Ok to recap, we have:

6500L FTs - made up of 2 x 2000L tanks, and 5 x 500L tanks - all polymaster (we have another 500L tank sitting idle if we need it too)

16 x 2 tier IBCs all full of water ATM and we guesstimate each one of the 32 tanks (top and bottom) is holding about 350L, with duckweed doing well in 9 of the top IBC tanks, and about 100 minnows swimming around in a few of those. We also have about 60 yabbies in some of the bottom tanks and 5 goldfish for mozzie control.

As the system builds up, (or when we have the gravel for them) we will change 6 of the top tanks to gravel GBs and 2 to Hydroton for carrots etc., The last 8 top beds can be converted over if and when we need them.

These 16 double IBC tanks are draining straight into the sump which is 1000L with a float switch.

Our GBs are 1/2 cut IBCs, and we have 21 of them.

So by my calcs (mind you hubby is the human calculator in the family so if I get it right Im doin' well!) if Im just working on the 6500L tanks at a stocking density of 3kg to 100L, and we are only planning to grow out to 500g, it will take just under 400 fish?

Not sure how much we need to factor in the yabby tanks as they are going to be so lightly stocked plus I belive that the extra water helps stabilise the system?

We were thinking of getting 300 SP fingerlings to start with and see how they go. Appreciate any thoughts...

11000 L of filtration
300 fish easy, then you can grow em out nice n big

thanks freoboy! ... I like 'em big

Received a high flow stem for our spider valve today which is filling the GBs heaps faster... thanks Rupe!

So hopefully we can have each bank of GBs filling closer to once an hour instead of well over 2

Yesterdays readings:

Ph - 8
Amm - 1
Ni - .25
Na - 10
Temp - 18 deg

Actually the Ni was below .25 but above 0... think I put 0 on the fishless cycling thread but its definitely tracing.

Glad to hear the beds are filling faster ....

You could always "pair" the oulets to the beds, and thus pump twice as often...

i.e... based on your diagram...

Pair outlets #1,#3 - to beds #1
Pair outlets #2,#4 - to beds #2,#4
Pair outlets #3,#6 - to beds #3,#5

No worries, thank for posting that Rupe.

Might see how the system goes over winter first... not too sure at this stage whether the drainage would keep up either!...have a lot of tweaking ahead me thinks

Test results:
Ph - 8.2
Am - .5
Ni - .5
Na - 40

Nitrates getting up, you should be starting to see some plant growth before to long..

And I'm sure you'll get to 100 pages.....

thanks EB...

Yeah, seeds have been seriously sprouting up everywhere for about a week now...probably didnt help that I double seeded the beds... (3 weeks after the first lot was thrown in I thought they must have failed so re-did them )

Have hundreds of lettuces sprouting... will have to do some major thinning in a couple of weeks time!

Hubby had a busy day today while I was in town, and plumbed up 5 of the 6 remaining FTs ... getting closer to being 'fish ready'

will take some pics tomorrow...

Saturdays test results:

Ph - 8.3
Amm - .25
Ni - Trace
Na - 40

Yesterdays (Mon) test results:

Ph - 8.4
Amm - .5
Ni - 0
Na - 20

All the FTs are plumbed in now ...pics

And check out the new sump tank cover! Hubby's surprise for me yesterday...

Damn you keep your DH busy......


Always amazed to see the new things happening at your place, nice neat plumbing work, your hubby really knows what he's doing...

How much was the big FT?

Thanks EB!!

... I just showed him your post and he is pretty chuffed. He is loving the AP system and is very proud of what we've put together... I am too - of it... and of him



(Zman - there are 2 big FTs (2000L), we got them second hand for $900 ea)