Backyard Aquaponics
A place to discuss aquaponics

Hi,
Been working on this for about 2 months now and starting to get somewhere.
Total budget $1000.
Big tank has 50 Barra and small tank has about 6 Koi and 8 goldfish.
Thanks for everyones elses posting on the forum it has helped me out a lot.[attachment=0]

Hi there and welcome.

Welcome AL.... 50 Barra.... how big is your fish tank.... and can I ask just what is the second half buried blue barrel... some sort of bio-filter??... or a sump?

Hi and thanks.

Yes the blue barrel on the left of the barra tank is a 200l biofilter.
Used to start the system and maintain it while grow beds are bought on line.

The tank is 1600l with a 6000lph pump running 2 x 100l growbeds and the bio filter continuously.

I have two baths and a 3rd half drum to add as grow beds but they will be run on a second pump with timer and auto syphons.

... how does your bio-filter work Al???... and what do you use as a filter medium?

Project overview.
Chooks and guard dogs

The Bio filter is top in - bottom out and has shade cloth and dacron as medium.
Dacron strips out the blue mettal dust very well but needs washing regularly pluss lots of surface area...

Tank construction.

Outback Ozzies system provided a lot of inspiration as did food and fish's ability to "find and re-use".

Looking good. i like the look of the green house.

Thanks for that Dufflight and Hi OBO

The few people who have been over to have a look have commented about the green house style too. Anyone is welcome to drop in just PM me.

It is an old commercial green house that was blown over in a storm and we cut the bends into half. It was given to me free by a friend!
(Thanks Markus.)
Pavers are leftovers from a friends drive, covers are a old dairy walkway ($5 ea), tin is from a garage I pulled down and removed for free. My biggest expenses have been clear sheeting and pumps followed by the fish and then a roll of black plastic...

The Goldfish are from petstock, the Koi from lotus blossum and the Barra are from Golden ponds. Barra were $2.50 each and are from the 60mm tank however most were bigger with a couple at over 100mm. I'm pretty happy with all supliers and have lost only one barra (unexplainable) and 2 gold fish due to canabalism.

Questions.

Most of the seedlings I planted in the new grow bed went soft and died already.
They were in for 4 days.
There is about 5ppt salt in that water which I am now diluting with 100 to 200l water changes daily untill all grow beds are on line to take up the Nitrate and nitrite.
The seedlings were about 4 weeks old and most were about 8cm high.
Were they to young or is the salt to blame or is it something else?

Water temp 25' (added second heater should bring it back up to 29 ish)
Ammonia 0.25
Nitrite 0.50
Nitrate 20
PH 7.4 to 7.6
(these readings were taken after 2 days with no water change. Been feeding hungry fish twice daily.)

So - Should I do bigger water change and or slow down feeding?

Will the fish be affected by the levels above?

Further grow beds are due in tomorrow (x1) and then probably about christmas day (x2 more) and I will probly transplant some established seedlings into them and buy some to get nitrates sucked up asap...

For future reference, only 1ppt of salt is needed to mitigate nitrites toxicity.

Were the seedlings getting wet enough? 5ppt is pretty high, but I wouldn't think the plants would keel over straight away unless they are a susceptible species. Usually 4 day deaths would be lack of water.

With your amount of salt your readings should not be toxic. Just be careful of the ammonia at your temps. Higher temp = badder ammonia.

Always slow down feedings, rather than changing water out. Let the system stabilize, then go for it.

Thanks for that OBO.

I was thinking it may be the opposite - too much water?

Anyway I bought some seedlings from the B that are more established and will let mine mature a bit more before planting out.

Also direct sowing some to see how that goes.

I got a bathtub hooked up as a flood and drain bed last night and it has some of the B seedlings in it.

It floods in 1.5 mins and takes 7.5 mins to drain - so if I run the pump for 5 mins approx every 2 hours overnight from 5pm to 7:30am and then approx every hour from 10am till 3pm should that be enough?

Actually Al.. I was thinking the same thing... flooding too high will wilt/damp off young seedlings in a couple of days....

Make sure that you're only flooding to about 25mm below the surface of the media... with direct sow seeds... just water them over with a watering can until they've settled into the media, sprouted and established a bit...

Thanks Rupert,
The losses occured in continuos flow beds, I adjusted to nozzels and spray pattern and added gravel to areas to try get more eaven coverage and not directly on the plants.
Will see how the latest seedlings go in there.
New beds are flood and drain, hopefully I wont have that problem
Any comments on the watering program for flood and drain beds below?