Hi Christine

Thank you very much for the information on your LR systems.

>We have considered similar
>technology for newer projects where specific conditions preclude the
>construction of a floating system. The benefits of the latter leave us
>inclined to opt for  floating systems. Restorers, for example, do not
>demand precious land, are less energy intensive (the height of water lifted
>is less) and can be more appealing visually (less conspicuous).
> (cut)
>I recall someone's comment about research priorites. I believe the
>determination of higher plants contribution to these systems is one
>sorely in need of attention.

In China, fish farming is now often integrated with aquaponics; i.e. plant/crop cultivation on floats. The main purpose of the plants is to absorb nutrients from the pond water and thus it has the same purpose of water purification to avoid eutrophication as with LR systems. The distinct difference is that the Chinese use commercially valuable plants (rice, flowers, vegetables, herbs, etc.)

Aquaponics in China has two main hurdles to tackle:
(a) the search for and use of cheap local materials or scavenged/recycled materials as floats. Bamboo has been used and with holes at the bottom half to allow water flow, it protects the roots of plants from fishes. The problem in using bamboo is that the material decays in 2-3 years. Also much labour is needed in the planting process as the plants are placed in each segments of the bamboo poles.  Styrenfoam have been used as floats quite successfully using sizes that are more easily handled.

(b) protection of plant roots from being eaten/damaged by fishes. One method is to put a net under the roots. The other is to sink the float to a certain depth of water so that water can flow into the enclosure and keeping the fishes out.

To Christine and the audience:
Do you have any suggestions on other possible alternatives and ideas that could be tested ?

regards
jacky foo