Backyard Aquaponics
A place to discuss aquaponics

My trout tanks all have a current in them as when holding fish at high densities there are many advantages to this.
1. Trout dont mind swimming into a bit of current.
2. Its the best and easiest way to remove solids from the tank.
3. Its an efficient way of providing uniform levels of DO across the tank, especially with wide tanks.

I also grow trout in static ponds and without exception the trout from these are much larger than those grown in the tanks. I am sure the major influences on growth differences are to do with stocking density, water temperatures and food availability not a lack of current. However I have yet to see any evidence both in nature and in an aquaculture situation that trout grow quicker/larger by having to swim against a current. In fact Earl Leitritz in his book (page 68) Trout and Salmon Culture states: "in large deep still pools, fish rest most of the time and food conversion is normally better than in narrow swift ponds where a good portion of a fishes energy is used in maintaining its position in the pond."

As I stated earlier if you have seen evidence to the contrary I would be very interested to read it.

Cut/paste from here (Fish under exercise) : http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3107430/
PDF: http://www.ncbi.nlm.nih.gov/pmc/article ... e_9505.pdf
Swimming in the future

It can thus be concluded that optimal exercise may have beneficial effects of major importance for aquaculture:

1 Induced growth by higher feeding efficiency, growth rates, and skeletal muscle mass.

2 Changes in muscle composition leading to higher flesh quality.

3 Increased survival by increased robustness or fitness; cardiovascular and respiratory performance, mitochondrial densities, and muscle tissue capillarization.

4 Increased welfare by lowered stress due to reduced aggressive interactions and stimulation of neurogenesis
.
5 Stimulation of immune status: exercise as a preventive health measure.

6 Reproduction control: triggering lipid mobilization, delay of sexual maturation, prevention of precocious maturation, and extension of the growth period.

cheers

Hmm very interesting sol tun

sent from my mobicologne

if you could train the fish to swim in a stationary harness
they could power a whirlpool affect in the FT and get fit at the same time.

a pump could be run from maybe a turbine or water wheel?

voila no more power bills.