Report from workshop in Keyser

I attended a workshop in Keyser, West Virginia which was organized by The Fresh Water Institute and funded by the Appalachian Regional Commission.

I jotted down some significant conclusions that I reached at end of the workshop:

Lifestyle Issues
1. Aquaculture is a 24-hour a day, 7 day-a-week, 365-day-a-year operation. Automatic feeders are wasteful and not reliable so somebody has to work weekends and holidays. Equipment can and does break down. And about that two-week vacation to France.... If you can do it with a partner it will make your life much easier. If you can set up the greenhouse adjacent to your home it will make those 3:00 am emergencies a little less painful.

Regarding equipment:
1. When possible, use flexible PVC pipe instead of straight to minimize fittings and provide more flexibility.

2. Order valves and solenoids from an aquatic equipment supplier rather than your local home improvement store. The quality is far superior as the cheaper models are very hard to turn.

3. Install shut-offs and by-passes in as many places in your system as possible. Plan ahead for the worst so that you can avoid a catastrophe.

4. In a flood and drain gravel operation it is not necessary to run your supply pipe all of the way around the bed. A T-shaped supply is adequate and possibly just a simple input pipe will be enough (this will require some additional testing to see if the flow of the water in will disturb the gravel and roots at that end). The lab at the school filled their beds with a simple T-configuration and it worked well, required less material and provided a larger planting area.

5. The outflow of water from the beds does not need to be controlled with any sort of float switch, simply installing a valve at the outlet and partially closing it will allow the bed to fill. Once the water coming in stops then it continues to drain.

6. Based on the experience of the Freshwater Institute staff with the establishment of several labs, one closely modeled after S & S, it is recommended that a solid separator be integrated into the system. Paula and Tom apparently have their system quite finely tuned and do not need it but in the one modeled after theirs they wish they had built it in. At a minimum, when planning a layout, leave space and connections to allow installation of a solid separator in the future. The bead separator that was installed in the cold water system looked very convenient.

7. When you lay out your equipment placement, plan ahead for expansion. Place your fish tanks and grow beds, etc. so that you can add modules without having to duplicate equipment or make unnecessarily long runs.

8. Invest in a sensa-phone or Radio Shack home security phone dialer to call you or beep you (always at 3:00 am I'm told) if certain parameters get out of whack - including pumps, water level, power, temperature. The cost is not too high ($150-200) and it will buy you a lot of peace of mind.

9. Have back-up equipment on-hand, extra pumps, etc.

System design
1. There are multiple system options including flood and drain gravel, floating beds and NFT. Flood and drain seems most appropriate for a majority of crops; flood and drain seems particularly good for lettuces. I visited and NFT operation on the way to the workshop and came away with the impression that since it uses such small quantities of water it takes a large operation to filter a good sized tank. If fish are not a major focus then this might be good. NFT is more vulnerable to a stoppage of water flow than the other systems. I think that you can combine different technologies into one recirculating system if there are operational advantages.

Questions I'm Left With
1. The labs that I saw use air stones in the fish tanks to oxygenate the water but I'm under the impression that Paula and Tom don't. Jim Rakocy also uses them in St. Croix. Are they really necessary?

2. The growing beds in Keyser were made out of heavy 2x12's and plastic liners. They are more economical than poly grow beds but are there advantages of the poly? Do you still need to support them with a frame and set them on a plywood base?

3. Would there be any advantages to using NFT gutters in a flood and drain mode? The advantage I see is one of compactness. The question is, does a 4-6" gutter provide enough space for roots?

4. One of our presenters had a large tilapia pond farming operation. His cost to produce a pound of tilapia was $.62. In a recirculating system the costs are much higher. Is it possible to grow tilapia in ponds (in the south) and have only the minimal amount of fish necessary to provide nutrient support for the plants in the recirculating system, thereby reducing your overall costs.

5. Most of the research on integrated systems is focused on maximizing fish production, identifying the smallest growing area required to clean the water for reintroduction to the fish tanks. What is the minimal amount of fish required to support plant growth? Paula do you think you've hit the optimal level with a 1,000 gallon tank to 6 4x8 grow beds? What is the minimum pounds of fish that you have to stock to keep the growing beds thriving?

6. Different varieties of tilapia have different yields of meat ranging from 25% to 35% or higher. It makes sense to identify the high-yielders since the same amount of feed will produce more meat and hopefully greater profits. Ornamental fish offer an intriguing alternative but it is a complex business with lots of players. If you can find a market niche this may be a good way to go.

7. Sexing of Tilapia is a delicate area - legally that is since the USDA has not approved the well-tested proven methods developed by researchers. Locating a source of testosterone is tricky.

8. Marketing is a major questions - 'I've been told that if you set it up the customers will come due to the unique nature of this operation. In my area there is a large hydroponic greenhouse operation under construction, the first in the area. My challenge will be to find a niche so that I am not competing directly with them since there are deep pockets involved.

I welcome your comments or suggestions on any of the above. I will not be able to respond until after the 20th when my 7 visitors leave town. Then I'll get serious about actually setting up a system using all that I've learned from this forum and from the workshop. Thanks to all who participate and to you especially, Paula and Tom.

Adriana