Backyard Aquaponics
A place to discuss aquaponics

G'day Gary, have been following Murray with the coco-peat and also interested in your input as well - keep us posted on how the bio-filter goes (pics obligatory )

A couple of days ago, I dismantled my four satellite pots in anticipation of moving them to my new growing deck. They had been performing poorly because they only receive morning sun - they are in the doorway of the shed.

On a whim, I tested my fish tank water......ph 6.4....Ammonia - 1.0..... Nitrites - 5.0(which my wife describes as a "pretty colour".......Nitrates - 5.0.

I confirmed that our mains water pH is 7.6.

I’ve been feeding particularly hard……I love watching the fish splash around on the surface as they grab the pellets.....and it looks like I'm overdoing it.

I changed about 150 (out of 700) litres and retested the water....ph is 6.8 ....Ammonia is 0.5........Nitrites are 2.0......and my fish have gone on a crash diet.

I made a couple of simple distributors out of plastic wash basins for my bio-filters which has improved the distribution of water that flows through them.

But for the fact that I have lots of air going into my tank, and the pH is so low (because I use usually use rainwater for topping up the tank), I probably would have had a disaster on my hands.

That is weird. I would have thought that ph of 6.4 wasn't quite low enough yet for the nitrosomonos and nitrobacter to fail. I guess as you have indicated, your biofilters haven't quite been doing the job as intended - hopefully the increased flow in the biofilters will rectify the problem Garry. To be safe I'd be inclined to add on a small continuous flow bed of gravel or clay balls to be safe. Aren't your biofilters full of oyster shell. It is weird that this has not kept you ph higher.

The bacteria that handle the nitrites are the more sensitive to both PH and low temps. IMO is not a case of bacterial failure, but the "slowing down" due to PH. Everything needs to be in quilibrium. If the colony is at a size that it can process all the nitrite at ph 7 and 25C and then the temp or ph is lowered over ashort period then there will be an inbalance between load / processing capability.

Steve

Thanks VB and Steve,

I think that, by removing the satellite pots, which were filled with clay balls, I dismantled a large part of the bio-filtration which was occurring.

The plants that I had in the satellite pots weren't doing all that well because they were located inside the shed door and only received the morning sun.

Steve, I agree that the system appears to have drifted out of the optimum pH and temperature range.....and has slowed.

I'm unsure as to why the oyster shells haven't been more effective in keeping the pH up.......particularly since prior to doing the latest little water change, I haven't added much water (other than a bit of top up) to the system in weeks.

I'm hoping to crank up some new growing systems in the next few days.
Unfortunately, I need to also move my tank to the opposite end of the shed......it's going to be a stressful time for us all.

Gary

Moving that tank will be easy if you can get your hands on a pallett truck or fork lift, it'll take a few seconds and you wont have to discard any water.

Hi Erik,

You're right! It would have beeen easier with a pallet or fork truck but I didn't know where to find one at short notice.

As it turned, I lined up every drum I could find....and a 150 litre tub.... and we pumped the fish tank water into these.

As the water level dropped, we caught the fish and put them in a 200 litre drum until the tank was light enough to move.

We gave the tank a quick wipe out and hosed it clean before carrying it to the new location at the opposite end of the shed. We also moved the bio-filters.

We weighed ten of the fish.......ranged from 50gm to 200gm.....average was 120gm. (When we got the fish, they seemed to be a range of sizes).

The framework for the growing systems is directly the other side of the shed wall.

Here's some pictures.....

There is exactly enough space in the corner to put another mega bin tank....our next projected move.

Here's a photo of our concrete flow forms......they are just outside of the framework photos.

Good one Garry. Are you using the flow-forms to assist in aeration? What other purpose will they serve?

I would add some more vertical pieces to that frame work... although if you are not using gravel it would be ok... I have noticed that material gains its strength by being attached to a flat surface, like colourbond etc. Stops it from flexing.

Anyway, nice progress and what the hell is that thing in your last picture? What was it for originally?

Flow Forms are a combination of science and art.

As water passes through the flow forms, it takes up a pulsing figure of 8 movement -very much like the swirling motion of a mountain stream. This action oxygenates and re-vitalises the water.

Polluted water (like greywater or fish tank effluent) contains high levels of nutrient which consume oxygen. We use flow forms to provide the dissolved oxygen required by the micro-organisms which break down the nutrients in the water. The flow forms are then used to ‘polish’ and re-vitalise the water to further improve its quality.

Flow forms are also used by Bio-dynamic farmers to mix their preparations,

Sculptural in appearance, the sight and sound of water as it vortices through a flow form is also good for the soul.

As you see, our flow forms haven't operated for a while (hence the leaves) but they are part of the medium to long term picture.

I'll ensure that they are operating in time for the next Brisbane Meeting.

And here I was thinking they were hobbit toilets?

Given the interest in flow forms, I'll start another thread.

Yeah Gnash me too... LOL