Backyard Aquaponics
A place to discuss aquaponics

Thanks R'OZ and chillidude.
What size could I reasonably expect Barramundi to grow to in my 80,000+litre tank if I started with, say, 100 x 90-100mm fingerlings in early November with a view to a late April harvest? I am aware that some species of fish grow larger, faster if they have more space so am hoping that a big FT and significant understocking might help me here.

100 fish in 80,000+Ltr... I'd be more concerned on how you are going to catch them at harvest time!

I hope you've got a snorkel and a gidgy!... or a baitcaster and some Mann's Stretch 10's... Scarlett O'hara is a good colour for Barra!

You could charge desperate sportfishing types to fish your pool... on a catch and release basis... they catch them then release them to your freezer!...

DandM have successfully grown Barra out in their 10kL pool. Temps ranging from 14deg - 28deg. After a quick seaqrch looks like they were going in around late October @ 500g and harvesting late March @ 1.5kg.

Id say go for it PJ

Yeah, if you can get 'em at 500g, you won't have any problem - that's a decent sized fish, not the 3/4 inch ones getting mentioned earlier.

Good point chilli

To get them to a edible size by April I recon you need to start with 150mm sized fish in late Nov\Dec. I see so many people with 5 to 6 inch Barra when I am delivering Trout in April/May who bought them as fingerlings in late Spring. Most of them end up going to their chooks or disposed of in other ways as they are still to small for eating, bit of a waste really.
Your other option is to source the Barra fingerlings in the winter and keep them in a heated aquarium or tank and move them to the aquaponics tank once the water temps are warm enough and they have put on some size. The other thing to remember with Barra is you really need to try and keep the water temps in the high 20's to get a rapid growth rate. Running some water through some black poly pipe can make all the difference.

It seems rather incongruous that, at the changeover between seasons, I would replace my ~350g harvest size Rainbow Trout with 500g starter size Barra! That is not likely to happen. I think I will look for Barramundi around 100g and grow them on from that size. If they only reach 500g, or perhaps 54cm in length, by seasons end then so be it - there is no minimum legal length with which to comply if you grow your own fish.
Mr Damage, my angling adventures start this weekend with my first foray into home grown trout harvesting via rod and reel. There are 96 of the buggers.

Hey PLJ with your very large concrete tank I would be checking what the water temperature is. I know that concrete swimming pools can keep the water very cold and I'd be wondering how long your water would even be warm enough to grow barramundi, may not be warm enough until after xams which might mean it is good for longer growing trout.

Charlie and I have discussed this issue previously, Faye, and he also suggested I keep the trout going. Up until now I have been keen on doing the trout/barra changeover but may have to reconsider, especially if the raising of Barramundi to a decent size will be problematic due to a short season because of my water temps.
I think I will go read my tank thermometer now, and then pull out a big roll of LD black poly pipe to see how I can rig it up, in line with Troutman's water warming tip.

I had an exciting experience with my Rainbows this morning but I will detail that event elsewhere. Shame I didn't have a video running.

C'mon , it wasn't the end of the world.
Still tasted good to me.

If you want them like this, then have to buy fingerlings and grow out in your heated aquarium (with insulated walls). However, be prepared to have a good filtration system as I have found Barra produce about 10 times the crap as Jades or Silvers. Killed these off at start of winter this year (20 of them) ended up with cramps in my arm 1/2 way through filleting them and had to put rest back in fridge until next day.

This is a batch to be harvested before next winter, Just put them into the large tank last week then the bloody weather turned cold again. Managed to keep the temps up with my 300m (19mm) poly solar heater (so long as have sunshine during day) and my 4 aquarium heaters at night.

with trout harvest fast aproaching i was begining to think about what to do next but barra sound like lots of extra work ... not to mention that i should have already got some to keep in the aquarium .....

more thinkin required i think

Cheers
pete

Just rang Golden Ponds and they have 3-8cm Barra for $4 each or 15-20cm Barra for $10 each. Hopefully they something in the middle of those two ranges when I am ready to kill my last few Rainbows in the next month. I'm not so much interested in Barra as I am in Rainbows again next year so guess I have to start weighing up the cost of Barra/Rainbows vs SP.

I would only need about 10 Barra for 300L of filtration hey? What would be the minimum size Barra fngerlings to get from October onwards?

100 mm ....

I would have thought that 100mm would be a good size to start with but others are saying larger, and some say much larger. I suppose it all ends up being a function of how quickly you think you can grow them and what size is acceptable to you at harvest time.
I would be ecstatic if I could grow a barra to the size of Chainsaw's (wow, 3.4kg!!!) but I would probably need to start with a 3kg fish in order to do it!