Backyard Aquaponics
A place to discuss aquaponics

Hi All,
Firstly, thank you to Rupert for having my mate and I visit recently. Loads to think about. Thanks mate.
Two questions: Is anyone using crushed recycled brick as a GB media? It's a product I got to lay as a path surface and screened of anything >12mm. I've rinsed it twice and since it has an irregular, coarse surface, I think it will provide a large surface area for bacteria microenvironment.
It is, unfortunately very tough on the hands. Keen to hear your thoughts.
Secondly, with regard to constant flow systems, I believe nitra sommona, nitrabacter and nitraspira are aerobic bacteria, so how is it that they survive and function in a flooded environment?
Thanks for your thoughts.
Jim

This system viewtopic.php?f=17&t=5046 used recycled brick for continuous flow and it worked well. The recycled brick is used as a base material with hydroton over the top in the last incarnation, but is now flood and drain. Not sure if anyone has used it on a larger scale.

I would throw the recycled brick into a cement mixer for an hour and that will take all the sharp edges off it.

Thanks for the link, Burnsey. The cement mixer idea is a good one too.
Jim

Be wary of mortar in the recycled brick. It will become a MASSIVE ph stabilizer at very high ph. Ensure the brick is clean.

I'd say put some of that washed brick in a container of distilled water for several days. Then test the pH. That could help you decide if it was ok for media. Any mortar or cement in there could affect the pH quite high, too high for most people to like it.

You're welcome Jim... hope you both went away inspired...

The bacteria live within the surface film attached to the myriad of microscopic holes/idents/roughness of the surface of the media Jim....

Being aerobic... as long as they are provided with the two basic requirements of oxygen and food... ammonia... they'll do their job...

The nature of aquaponic systems is that they provide both those requirements...

Particulary in flood & drain systems where oxygen is continually sucked into the water via the drain cycle... whether by siphon or overflow standpipe...

Continuous flow systems... and/or DWC systems... usually required additional oxygenation in order to perform as well as flood & drain...

Usually the deployment of air stones within the fish tank... or, in the case of DWC... within the channels and/or solids digester... is sufficient to provide the oxygenation required...

Hope your trout grow big and fat Jim...

Jim

For a source of clean brick check out your local brickworks. There is a lot of edges etc get knocked off in manufacture.
Rumbling them for a short while soon takes off the sharp edges (leaves a bit of sludge in the mixer though)
I cheated on my last system and went to poly bottle caps covered with hydroton.

I like the poly bottle caps Sleepe - nice and light. I kept all the ones you had under the crushed brick which is under the hydroton. I will get some photos of the finished system and post them so ou can see it, did not realise I never posted completed photos till I linked the thread to this one last night.

Thanks for the replies.
Tested pH of a water sample after a week of having added rinsed brick. It's 7.0, which is the pH of the bore water we have.
The bottle cap/hydrotron idea sounds clever. I might try and sourse some myself.
I've got to get to Melbourne and pick up some Tilkey GBs.
I think I'll plumb a flood and drain system and see how it goes.
Cheers
Jim

Sounds good.

That pH reading on the bore water. Is that testing it right out of the tap? Or is that what it reads after sitting out for a while? Bore water with a pH of 7, wow that seems like a rare thing.

In any case, if the water reads 7 after sitting out with brick bits in it for a week, you are probably ok then since obviously there probably isn't any cement mixed in there or the pH would have gone up.

TC,
Our little town is on a bore. Calcium and magnesium salts. I can't remember exactly what the GH and KH measures where when I did them a while back, but they were moderate. The water is treated with potash to modify the pH after it's UV treated to render it micro organism free. No chlorine or chloromine which is good.
Jim