Backyard Aquaponics
A place to discuss aquaponics

I have several fishponds measuring from 1000-2000 square meters each with a depth of 1 meter. They are stocked with tilapia at 4 fish per square meter. Biomass at the end of the growing period would be about 1 kg per square meter and the daily rate of feed is 3% or 30 grams per square meter. My question is: Are the parameters sufficient to grow veggies on styro rafts inside protective hapa nets in the pond? Thank you all.

What is the water cycle in your ponds? As in are you changing out water in order to keep the water quality good? Do you have pumps and bio-filters? Or are you running water to waste with a river or something?

Aquaponics is a recirculating aquaculture method that uses plants to take up the excess nutrients. Normally in Aquaponics one needs some sort of pumping to send water through filters (solids filters and bio-filters) and help aerate it.

You could always try a small raft with some lettuce growing on it to see if your current set up would support the plant growth. I suspect you may need to add some extra aeration though if your nutrients are high enough to support plant growth.

If you've got 4 fish per square meter and expect a biomass of 1kg per square meter after grow out....

Does this mean you're only intending to grow each Tilapia to about 250gms???

Yes that is correct, we harvest at 250g after 120-150 days because that is the demand in the local market. The ponds are equipped with paddle wheels to increase aeration. No pumps or filters. We do not change water during the entire cycle but we do replace water lost by seepage and evaporation.

I do have a few styros there now for experimentation since last week but it's too early to tell.

I wonder how the Incas did it.

THANKS FELLAS.

Where is Silay City?

The Phillipines TCL

Do you use algael bloom management Cris???

Hi Rupert. We do not encourage algae growth in ponds with hapa nets as the nets get clogged with algae fast and interferes with water movement and oxygen supply. We do encourage algae growth in grow out ponds by proper pond preparation with lime, fertilizer, manure and weekly or bi-weekly application of fertilizer. Cheerz.

OK... Suspected that algael bloom is not what you'd want with hapa nets...

Reason I asked the question related to the fact that you're not filtering the pond in any way...

If you're not utilising algae to convert nutrients... and not getting any bloom... then I'm wondering if your stocking level and nutrient load would be enough for raft production...

Thanks Rupert. That's one aspect I didnt' think of. Time will tell when the experiment goes 30 days or so. Will keep you up to date.

I have a similar question(s). I have a large pond (maybe 750 ft x 40 ft) 15 ft at the deepest spot, overall about 4 ft deep. It is currently frozen but under the ice are catfish and carp.

Once the ice thaws can I use the water for AP? My two thoughts on how to do this would be pumping the water into a grow bed or pumping water thru pvc tubes a la NFT (but the solids need to be removed first thru gravel?).

In order to float plants on the pond directly would I need an air pump running under the plants?

I ordered a kit to test the water. I guess I'm looking for middle pH but what about the other levels?

Anyone else have a similar setup?

take a look at sminfiddles thread...he is working on that same setup now:
viewtopic.php?f=18&t=5862&st=0&sk=t&sd=a&hilit=texas+walk+in

Well, mine should be simpler than sminfiddles because the pond is so big I don't have to do anything (no pumps or feeding the fish). From what I can gather I need to:
1. pump water from the pond to a gravel grow bed to filter out the solids
2. use the water that drains out of the gravel GB for a NFT system.

Here's a pic of the pond:

Maybe float growbed pontoons or hang them off of a dock if you have one? Something like the OceanArks bioremediation stuff?

OMG! They're even based in Vermont. Way cool.
http://www.oceanarks.org/Ecological_Food_Production.php