DaveOponic - in Brunei

[DaveOponic]

I have about 20 Tilapia and they are growing very quickly. Here in Brunei the water temp. is usually around 27 - 30 Celsius.... at least that's what it is in our swimming pool. I have a concrete fishpond at the end of my verandah and probably a bit cooler in there.

I have about equal numbers of Koi and Black Tilapia. The Tilapia seem to be outgrowing the Koi. I'm groing Basil, Cucumbers, Radish and lettuces in 4 inch sewer pipe and in a PVC drum grow bed with clay pellets and charcoal substrate. the charcoal filters the water beautifully.

Maybe I was just lucky but haven't had any problem with water quality, PH, or cycling. My pond was well established before growing any veges and then just hooked up the pump and everything worked nicely.

Previously I was doing Hydroponics for the last two years. Had lots of successes and failures. Mainly getting the right nutrient mix as there are no suppliers of Hydroponic nutrient here in Brunei.

I am currently expanding and looking at a 1000 litre PVC tank. I'm going to need it as the Tilapia are soon going to get too big for my bathtub sized pond. I'm also getting interest from friends about buying fish.

No Tilapia in Qld? Too bad! They are the 3rd biggest selling fish in the US. But I can see how easily they could take over from native species, they sure are voracious eaters.


Dave

[GaryD]

Hi Dave,

I'd be interested in more details (and photos) of your charcoal filtration arrangement.

On the one hand it is a bit of shame about Tilapia, but then if it's a choice between Tilapia and native species like Barramundi, Jade Perch, Jungle Perch, and Honey Perch (and it is), I'll stick with the locals.

Gary

[DaveOponic]

Hi Gary

I have used half a 200 litre PVC drum and half filled the drum with BBQ charcoal, washed a few times first to remove fine particles. The top half is filled with expanded clay balls. A friend suggested it as a cost cutting idea as it saves on clay pellets. I only realised the filtering benefit once the system had settled in (cycled?) and clear sweet water flowed out of the drain pipe into the pond. A few days later I saw our cat drinking the water from the pipe. I have been tempted to try it myself as it looks so clear!!

I'll try and post some photos. You can see my system in my first postings on this forum.

Dave

[inzane]

BBQ charcoal, interesting. I wonder how much absorptive effect it will have, its usually pretty porous....

[DaveOponic]

Here in Brunei the BBQ charcoal is very cheap. fairly chunky pieces and varied in size and shape, so I reckon there is a lot of air space under my plants and no doubt filling with roots and good bacteria... maybe even worms. I like the idea that everything is now organic after a couple of years experimenting with Hydroponics, I am back to organic gardening again. Some friends even commented that I was somehow giving up my values by using chemical nutrient.... now I don't need to pay every month for that fertiliser anymore.

Last time I went to Sarawak I visited a Chinese organic food shop. The old lady there had a sparkling clean aquarium with baby Koi and some other smaller ornamental fish. No filter! She had several huge chunks of charcoal in the water and claimed that it was keeping the fish healthy and the water clear.
She also had water chestnuts floating in the top of the water.

When I lived in Indonesia, if I got a tummy bug (diaroea) I would take charcoal tablets. they absorb the nasty bugs and within hours you feel OK again. Charcoal filters are also used widely in Asia for clearing up drinking water and removing single celled parasites.

As far as removing the nutrient, I am not sure. I'm not a chemist and I rarely measure Ph or PPM in my system. So far everything has been bubbling along nicely. My fish are very healthy and good appetites. No parasites and water is always crystal clear.

The clay pellets also absorb a lot of water. There is always green algae growing on top layer of clay balls and doesn't seem to do any harm.

PS. To control the algae in my pond/s I have put in several Sucker Fish. They are sold here as Borneo Suckers but not sure waht the species is or if you can get them in Australia. Local aqaurium shops always have two or three in each glass tank and they spend their time attaching their mouth to the glass and eating all the algae. they are doing an amazing job in my pond.. the bottom and sides are always clean now.


Dave

[GaryD]

Hi,

As far as removing the nutrient, I am not sure.

Charcoal will act as the feedstock in a denitrification filter. These filters are used to remove nitrates from water. The carbon (charcoal) oxidises nitrates in an anaerobic (without air) environment and converts them to nitrous oxide (laughing gas) and then straight nitrogen (as a gas).

Charcoal is widely used in aquarium filters, too.

Gary