Backyard Aquaponics
A place to discuss aquaponics

If your pH has gone from 6.8 -> 6.0 overnight... I'd be a little concerned...

Perhaps get some shell grit and place it underneath the growbed inlets... or sump return...

I thought the shell grit buffered the ph so before i put the fish in i put a bucket with holes in the bottom, about 12 litres of it. At that time the ph was around 6 and slowly came back to 6.8, i'd been putting in a small amount of powerfeed and seasol to give the bacteria something to start on. funnily when i put the fish in i'd stopped putting the fert in the Rates rites and ammo had dropped to zero and the ph had risen to 6.4 from 6. It then kept climbing to 6.8 when i overdsed the powerfeed, which resulted in a ph plummet to 6.

Maybe there is something in the powerfeed?
or
Does a system naturally move to acid?

More Pics of construction

AP system can tend toward acidicy... but not rapidly... I'd say there is something in the Powerfeed... I'd suggest not using it... just stick with straight Seasol...

pH 6.8 if a perfectly fine value... and with a few kilos of shellgrit it should stay around that mark... or might even drift toward 7.4 over time...

Beatiful thanks Rupe.

SP fingerlings are 2 weeks away, the plants just have to hang there until then.

They'l be fine.

System looks nice except for the galvanising.

Yeah I'm not convinced about the dangers of the Galvanizing, isn't Eb's system made of galv? and i saw any from a member in the US who had rolled round galv beds. Also didn't our gand parent use galv water tanks of years without dying, although they all died eventaully but i don't think it was the galv. Has anyone tested water from a system with galv or tested the dead fish? Can this be done? who by? where from? how much would it cost?

I just really like the design.

A1 -someone has
2 and tox screened fish but not at the same time
3 sure
4 some one who can do it
5 where ever they live
6 Lots
... sorry couldn't resist

Not exactly the answers I was look for but i love your work!!

Erro, you're correct that Joels system is based on corrugated rolled galvanised tanks... are are other members...

You're also correct that such tanks were used for years as rainwater storage tanks...

But the tanks used today, while galvanised.... are line with a plastic coating or aquaplated... because of concerns as to the zinc component on peoples health...

Joels tanks are the newer "aquaplated/aqualined" tanks... as are all new tanks...

Hope this helps...

Oh well, enjoy your dead fish in 6 months

Ah yee of little faith!!

No - Obviously you have not read the threads that I have

Just think of how similar zinc is to lead.

Hi Erro - what is under the gal for support. It's not just the lip holding them up is it?

I'm sorry, but the unlined Gal is going to be a problem for you mate. SHame you didn't post more about your plans before you put the gravel in, we would have set you straight

No support I was going to put timber cross bar in but didn't seem to need it. The galv is 2mm so it is pretty strong and heavy.

No dramas i will use the galv for the Worm farm and switch the beds over to plastic when i get to stage two.