In science and engineering it is very common to develop ways of describing things so that when people use certain terms or descriptions everyone who is familiar with the naming system:
a. knows how to describe something accurately
b. knows exactly what a description means when they read it.
The best examples are for things like the rules involved in naming chemical compounds, different classifications of stars and the like.
To that end I started describing two things about grow beds (GB (Not gravel beds because they may not contain gravel)) the way they were filled and the way they where operated.
There are essentially two ways a GB can be filled constantly or intermittently. In a GB that is filled constantly there is a constant flow of water into the GB it doesn't matter how the water is handled once it is in the GB what matters is whether the water is delivered constantly. In a GB that is filled by a pump connected to a timer or by a siphon from another bed then the bed is filled intermittently by a flow that stops and starts. Again it doesn't matter how the water is handled once in the GB what matters is whether the water flow into the bed stops and starts.
The terms for this are:
Constant Flow = CFw; IFw = IFw.The second thing that I think it is important to describe is how the water is handled in the GB. There are many more ways of doing this and they include:
Constantly Flooded = CFd; Filled and then drained (Flood and Drain) = FnD; Constantly drained or draining = CD; Filled and then partially drained = FnPnDxx%.For the last one one you can specify the % of water that is drained from the GB.
When you put the terms together you can quickly and succintly describe the way in which a plant growing component is operated.
CFwCFd = A plant growing component that constantly has water flowing into it and the water level is maintained at a specified height. DWC tanks and some media beds are operated this way.
CFwFnD = is your standard bed that has water constantly flowing into it which is periodically emptied by a siphon, valve, weir gate or some other manner.
CFwCD = is where the flow is constant but the water is not allowed to build up in the plant growing area, NFT, strawberry towers, Rockwool tomato culture and the like are operated this way.
CFwFnD30% = is where the bed is fed by a constant stream of water but instead of being fully drained it is only partially drained by 30%. The only example I have of this is my CFwFnD Gb that is only partially drained because the sump is too small and the DWC sump extension that I had planed never happened.
IFwCFd = is a bed that is intermittently fed water but is kept constantly flooded a good example is here http://www.dryhydroponics.nl/ or the autopot system is another example.
IFwFnD = Where the flow is turned off and on and the bed drains while the flow is turned off. Your standard bed that is filled by a pump on a timer fits in this category.
IFwCD = is where the flow is turned off and on and water freely drains away without being retained in the bed. Examples of this are often media systems where they are fed by timers or moisture sensor that activates a pump.
I can appreciate that this system is not for everyone but nomeclature systems like this that are explicit and precise give me a warm fuzzy glow in my anal retentive heart
