Backyard Aquaponics
A place to discuss aquaponics

There you go !

Only really a couple of thin bamboo stakes.... although "Scottie" raised a question about them early on.... could be copper though... the old "koppers" logs and other "treated" pines were CCA.... copper, chrome, arsenic....

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Note a couple of other things as well Peter... you say you painted your growbeds with "acrylic paint".... what exactly did you use... inside and out???

Next... pics show an uncovered patio... with possibly "treated" wood.... is it still that way??

wehat a bastard... it has to be contamination of some sort, we think the painted gb's have done it. I think it is possible the paint was leaching over the last months, when it got to a critical level it nailed the fish. It's just a theory, but in absence of others I would empty the growbeds and paint over the acrilic with bitumen paint, leave them for a couple of weeks and rinse then try again. It is pretty drastic, but if you go putting fish in there again now, I reckon they will meet the same fate. If you want some supercheap feeder (but healthy we bred them) goldies to test the water with, let us know and I will drop some down.

It's hard to imagine that a little bit of drift from someone spraying next door would cause the water to change colour. Likewise it's hard to imagine that leeching from 2 skinny bamboo stakes would do that either. Not sure about the acrylic paint breaking down?
Peter has your pergola got a solid roof or do you get some rainfall in there dripping off of some treated pine? Do you get your water from the tap or tank?

Does this mean that the next Adelaide meet wont be at your place?

Just a thought the fish tank with the hinged lid how about a buildup of carbondioxide [not enough oxygen ] i allways run air stones

The airstones would be pushing out air as it's added ,, so can't see that build up happening.

Were the fish's gills very dark???

Nah.... so would tend to rule out DO, Nitrite poisoning, Ammonia and CO2.... think the water colouration is the "key"..... definitely a "contamination" issue IMHO....

Agreed Rupe ,, pinkish gills rules out quite a few things,.....,

The "suddeness " of it is surprising ,, slow leaching would normally kill the weaker first , at least a few hours if not days between killings ......
Looks like a sudden influx ,, that might be the clue to trace this,.....,my dear Watson.

Water coming from stormwater?

How loud is your pump ? How friendly is your neighbour?

Thanks for everyones comments, ideas and concerns.
The speed of the disaster is what still has me stunned.
Last Monday they were all fine as the grandkids and I had a good close look at them.
On Tuesday I noticed 6 or 7 swimming on the surface (not gulping as I have two airstones running 24/7)
and when fed they jumped in for their share. (unusual to see them on the surface).
The slight brown discolouration was evident but could still see most of the others swimming around the bottom of the tank.
I didn't check the next day as the wife was in hospital.
Thursday at noon they were all dead.
In reply to some of your suggestions:
Six thin green dyed bamboo stakes have been use to support veggies, but they have been in for 6 months with no issues.
The uncovered pergola above is CCA pine but has been up for 8 years in the weather so it's doubtful that any CCA would still be leaching. Besides, only a few mm's of rain in the last week.
The paint on the inside of the GB's extends only about 50mm below the gravel level and has been there for 8 months...again, it seems too long to suddenly take effect.
There was a buildup of solids at the bottom of the tank and maybe that load just got too much.....although I thought this would show up in the test results???
I suspect we will never know so have today thoroughly drained and cleaned the tank and sump, refilled with tank water and added 8 goldies from my pond.
I won't cycle for a few days while they settle and will keep the veggies going with Seasol.
I do need to find a better way of flushing/pumping the solids.....need mini creepy crawly.
Stu, thanks for the offer of feeders but I have 50 or so home grown goldies in the pond so will use them.
Thanks again for everyones input...it's nice to have the support.

Could the grandkids have been a factor?

Hey fishy, you look thirsty. Here have some of my soft drink...
Hey fishy, you look hungry. Here have some of my vegimite sandwich...

Only a suggestion, I'm sure your grandkids wouldn't...

ha