Flood and Drain speed?

[wh33t]

Every 30 minutes is about right. Faster means you are pumping more water than you need and wasting energy.

Yea, I'm using the smallest pump I had laying around. I just gave away a small 5w pump which probably would have been perfect for a cycle every 10 minutes or so.

[badflash]

You can bypass flow back to the sump to limit flow to the bed.

[wh33t]

You can bypass flow back to the sump to limit flow to the bed.

Yes, I could also put a valve in and limit it that way, but that's kind of a waste of energy, puts extra strain on the pump and also causes my water to heat up doesn't it?

[keith_r]

i think badflash means that you can add a T to after the pump outlet (add a valve) and direct some flow back into your ft (i do this as well)
that will add additional aeration as well

[badflash]

Correct. You need to look at your pump curve to see the effects of thottling vs bypassing flow. Either may increase or decrease power. If you have a 600 gallon system and an 80 watt pump, heat isn't an issue.

i think badflash means that you can add a T to after the pump outlet (add a valve) and direct some flow back into your ft (i do this as well)
that will add additional aeration as well

[wh33t]

I have a 10 gallon system and a 7watt pump... How am I doing? Lol.

[tyrtaeus]

It appears that I have been a dunce. I have been drawing out a system ("Farming is easy when your plow is a pencil and your tractor a desk chair"), and always assumed I would need a timer to cycle a pump off and on.

It seems like you all are suggesting a lower flow pump, always on, that is small enough that the bell siphon pulls it dry for 30-45 minutes of the hour. That simplifies things immeasurably.

It seems flood and drain is the most widely used system, but I was considering a drip or constant flow system as I was having the devil's time finding a 12 Volt timer.

Thanks for turning on the lightbulb.

[rfeiller]

i believe aeroponics will produce the best results, but bioponic, aquaponic, and vermiponic water makes a mess of the system. roots develope differently according to the media used. submersed roots, roots developed in soil or soiless media each take a different shape. in soil or soiless media you will find that the very tip of the root actually obsorbs the nutrients and moisture, the rest of the root is structural. in bonsia by cutting the roots back each single tip will develop at least two tips, this method is repeated over and over to produce many short roots each with an active tip providing nutrient and water to the tree. in hydroponics sacks are designed to air prune the roots, this accomplishes the same thing that trimming the roots in bonsai. long roots are actually a detriment to the health of the tree/plant. plants and trees suffer from circulartory problems also that is why many of them die. a tree that will live less than a hundred years normally, in bonsai can live 400 yrs.

orchids can not have their roots submersed for long periods of times, the exterior of the roots have the ability to grab moisture as epiphylums. roots in aeroponics do not need to grow long, so they develop enlarged filiments that are able to grab these nutrients and moisture.

[urbanfarmer]

i believe aeroponics will produce the best results, but bioponic, aquaponic, and vermiponic water makes a mess of the system. roots develope differently according to the media used. submersed roots, roots developed in soil or soiless media each take a different shape. in soil or soiless media you will find that the very tip of the root actually obsorbs the nutrients and moisture, the rest of the root is structural. in bonsia by cutting the roots back each single tip will develop at least two tips, this method is repeated over and over to produce many short roots each with an active tip providing nutrient and water to the tree. in hydroponics sacks are designed to air prune the roots, this accomplishes the same thing that trimming the roots in bonsai. long roots are actually a detriment to the health of the tree/plant. plants and trees suffer from circulartory problems also that is why many of them die. a tree that will live less than a hundred years normally, in bonsai can live 400 yrs.

orchids can not have their roots submersed for long periods of times, the exterior of the roots have the ability to grab moisture as epiphylums. roots in aeroponics do not need to grow long, so they develop enlarged filiments that are able to grab these nutrients and moisture.

From the perspective of a biologist, I would only guess they trim the roots because they trim the leaves. To maintain a healthy plant, tree or otherwise, a specific root to leaf ratio must be maintained. You can't just trim the leaves and not the roots...

Anyway, I have to disagree with your anecdotal evidence here... the circulation of fluids in a plant, unlike a human being, is not based on pressure overcoming gravity and friction. In fact, a plant moves fluids through intermolecular forces on such a small scale that gravity is a relatively insignificant force. Comparing to the electromagnetic force to the gravitational force we see:

Electromagnetic force: 7 x 10^-3 (units of relative force)
Gravitational force: 6 x 10^-39 (units of relative force)

The difference in forces here is 100,000,000,000,000,000,000,000,000 roughly...

The reason why this is important is that the entire inside of a plants phloem/xylem is filled with little "machines" that provide the force all the way up and down the vascular system. So, it really doesn't matter how long it is.



AND, here is my anecdotal counter-evidence! HARUMPH!

00:12:43 Next on our underground journey, the world's deepest tree root-- 400 feet down.
00:12:53 Mpumalanga, South Africa.
00:12:55 On a cliff above Echo Caves stands a grove of 150 year old fig trees.
00:13:01 These have survived a dual challenge-- growing in rock with no apparent source of water.

Not only is this the world's deepest tree root, it's the world's deepest hydroponic setup... and it wasn't even man made!

REFERENCES
History Channel. Journey to the Earth's Core. (4/2/2011) http://www.livedash.com/transcript/j...2_2011/578684/

Georgia State University, Department of Physics and Astronomy. Fundamental Fources http://hyperphysics.phy-astr.gsu.edu...es/funfor.html

[rfeiller]

The ratio of top trimming to root trimming is to insure a root system to provide nutrients and water to the branches. If the bonsai tree were in a grow bag the roots would be air pruned and trimming the branches would not be necessary except for design.