Backyard Aquaponics
A place to discuss aquaponics

Hello All,

I'm new to this forum and to Aquaponics as well. But currently involved in starting up a BIG aquaponics project in Ethiopia. We're starting up ten's of backyard aquaponics systems in different towns. It's run on a microfinance loan and I'm here to start it up correctly, building and starting together with the involved people.

Last year the organization has build a test system, which was not functioning properly when I arrived. The fish are growing, the pH seems good (averaging 6.8-7.0) but the plants are hardly growing.
Leaf burn is common and yellowing of the edges as well.

At first the leafs didn't look wel so I started adding IRON CHELATE. After consulting the some forum posts I concluded that I might have an Pottasium deficiency as well. So I produced potassium from Ash (soaking it, boiling it, cooling it) with a little positive succes.

Any ideas how to solve this? (I might be able to get Potassium Sulfate from a farmers here). I would like a laymens solution that could also be applied by all the people we are reaching with the project

I heard feeding banana's (does that work?)

SEE PICTURE
On the picture one can see only 2 IBC tanks with fish, there is a big 3000 liter tank as well just outside of the image. The systems has 2 half IBC tanks as media-beds and one concrete media bed of 4mx1m

Welcome to the Forum EthioPONICS .

Don't bother with banana's, they don't have enough potassium to do anything useful. I think somebody did the sums on here, and you'd need 500 banana peels to feed one tomato plant (from memory).

How old are the plants in the pictures? They look a little light coloured, but different types of lettuce do that naturally.

How is the water circulating through the beds as well?

These plants (small onces on picutre) are there already 4weeks, and still didn't grow more than 8cm.

The water circulates from 3 fishtanks (total=4000liter) through mediabeds (total 6m2) towards the Floating Raft system ( 5x5m).

Welcome to the forum.

How many fish and what size?
Are you filtering solids?
What do the roots look like?
Air Temperature? Day and Night.
Water temperature?
How are you aerating the water?

In my experience, a brand new aquaponics system without any seed material from an established system can sometimes take a while to mature and start producing.

..
And are you aerating that large DWC... and what is the construction... the setup looks wrong.. (judging from the black material)
Were it segmented.as a continuous race and water entering at one end and exiting the other, it would do far better.
It seems.to be stacked blocks with plastic or rubber draped over
There seems to be a pipe in the foreground, and looking like a water entry, and so where is the drain - back LH courner I suspect.. from the better growth in the LH channel

and, I wonder if there is sufficient light under that material
..

Hi EP... just bumping to ask what growth is like in the media beds..
..
.

Sorry for the late reaction (getting internet can be quite difficult)

- Solids are only filtered with a sedimentation filter between growbed and fishtank
- Roots are arbout 4cm and there seems to be kind of white fungi connected to it (or just tiny roots I'm not sure)
- Air temperature around 28-30C.
- Water temperature 20C? (not sure)
- No aereation in the DWC only in the fishtanks

- The system is currently one year old
- 16.5 KG of fish (four different sizes from seedlings to big ones, around 200 fish in total)

Growth in the media beds is good (squash, basil, chinese cabbage and cucumber are doing fine)
Many(!!) worms in the media beds, growth in FLoating Raft is limited.

You're right, just blocks with plastic foil.
No aeration of the DWC

viewtopic.php?f=3&t=26350
Picture swith plant colouring

[quote="EthioPONICS"].....Growth in the media beds is good ......growth in FLoating Raft is limited./quote]


Have you thought to change the layout of the DWC.. It seems to be so VERY wrong, and should flow like a snake.. AND you really do need AIR.. every good DWC that I have seen , has AIR supplied constantly.
..
.

what do you mean flow like a snake?
as in the plants? flow like on a conveyor belt?

i dont think that will do much to help his growth.

To change that now will be a very complex task, do you really think it's that necessary? It will mean a big investment + sort of restart of the system I'm afraid...