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wh33t
03-14-2011, 10:18 PM
Hey guys,

Quick question for you experienced guys out there.

How often do I want to fill my tub? Every few minutes? Currently it's about every 5 minutes.

My current setup will drain my flower bed in about 1/3 the time it takes to fill it.

wh33t
03-14-2011, 10:30 PM
Update, nevermind. It's a lot quicker than I thought, it's about every 2 minutes and 30 seconds.

urbanfarmer
03-14-2011, 11:17 PM
In my opinion, it doesn't matter much. The greatest benefit the flood/drain gives is the vacuum effect that forces highly oxygenated air into the lower grow bed area, which causes everything to thrive. So, as long as it floods and drains, you are fine! :mrgreen:

wh33t
03-14-2011, 11:36 PM
In my opinion, it doesn't matter much. The greatest benefit the flood/drain gives is the vacuum effect that forces highly oxygenated air into the lower grow bed area, which causes everything to thrive. So, as long as it floods and drains, you are fine! :mrgreen:

Excellent reply man. Thank you for your advice. I presume as long as the roots stay wet the speed doesn't matter.

urbanfarmer
03-15-2011, 09:10 PM
In my opinion, it doesn't matter much. The greatest benefit the flood/drain gives is the vacuum effect that forces highly oxygenated air into the lower grow bed area, which causes everything to thrive. So, as long as it floods and drains, you are fine! :mrgreen:

Excellent reply man. Thank you for your advice. I presume as long as the roots stay wet the speed doesn't matter.
That's one aspect of it. You do NOT want to let the roots dry out. That is the fastest way to kill your plants! The other aspect is that if the plants are provided a constant flow of nutrients, even at low concentrations, they will still be readily available and allow the plant to stay healthy while cleaning the water for the fish. I have seen some home experiments that suggest that stopping the flow for short periods of time is more beneficial than constant flow or flood and drain, but I have yet to see such research in a published journal etc... and in fact have seen research published to the contrary, but not in direct contradiction to the fact... anyway too much info... yes, doesn't matter, just don't let it get dry!

wh33t
03-15-2011, 10:52 PM
In my opinion, it doesn't matter much. The greatest benefit the flood/drain gives is the vacuum effect that forces highly oxygenated air into the lower grow bed area, which causes everything to thrive. So, as long as it floods and drains, you are fine! :mrgreen:

Excellent reply man. Thank you for your advice. I presume as long as the roots stay wet the speed doesn't matter.
That's one aspect of it. You do NOT want to let the roots dry out. That is the fastest way to kill your plants! The other aspect is that if the plants are provided a constant flow of nutrients, even at low concentrations, they will still be readily available and allow the plant to stay healthy while cleaning the water for the fish. I have seen some home experiments that suggest that stopping the flow for short periods of time is more beneficial than constant flow or flood and drain, but I have yet to see such research in a published journal etc... and in fact have seen research published to the contrary, but not in direct contradiction to the fact... anyway too much info... yes, doesn't matter, just don't let it get dry!

Coming from a hydroponics background, that is the same advice I give to people as well. But I have also heard that there is some kind of aeroponic aspect to letting the roots get partially damp, as opposed to wet. It encourages their roots to turn fluffy white which apparently allows them to grab small micron sized droplets of water directly out of the air... or something like that.

urbanfarmer
03-15-2011, 11:49 PM
Hm, that probably has to do with letting the little hair like strands stand up. I have seen this in new seedlings that have outgrown their peat puck. When I water them lightly the hairs seem to melt, probably collapsing under the minute weight of the water. I guess it's time to read my botany book that I have been putting off...

wh33t
03-16-2011, 12:53 AM
Hm, that probably has to do with letting the little hair like strands stand up. I have seen this in new seedlings that have outgrown their peat puck. When I water them lightly the hairs seem to melt, probably collapsing under the minute weight of the water. I guess it's time to read my botany book that I have been putting off...

I have seen full aeroponic systems where the roots look like balls of cotton. I do believe it has to do with rapid nutrient uptake. Aeroponics was introduced by Nasa I believe as a way to grow food in space. I think Aeroponics is the most aggressive way to grow a plant.

urbanfarmer
03-16-2011, 11:14 AM
Hm, that probably has to do with letting the little hair like strands stand up. I have seen this in new seedlings that have outgrown their peat puck. When I water them lightly the hairs seem to melt, probably collapsing under the minute weight of the water. I guess it's time to read my botany book that I have been putting off...

I have seen full aeroponic systems where the roots look like balls of cotton. I do believe it has to do with rapid nutrient uptake. Aeroponics was introduced by Nasa I believe as a way to grow food in space. I think Aeroponics is the most aggressive way to grow a plant.
There's no gravity in space. :mrgreen:

Try to do this at home and see what happens!
http://www.youtube.com/watch?v=Fg1RMEIP6i4

badflash
03-16-2011, 06:33 PM
Every 30 minutes is about right. Faster means you are pumping more water than you need and wasting energy.

wh33t
03-16-2011, 07:09 PM
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
03-17-2011, 06:41 PM
You can bypass flow back to the sump to limit flow to the bed.

wh33t
03-17-2011, 08:36 PM
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
03-18-2011, 05:46 AM
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
03-19-2011, 05:50 PM
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
03-19-2011, 06:06 PM
I have a 10 gallon system and a 7watt pump... How am I doing? Lol.

tyrtaeus
04-23-2011, 07:08 PM
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
04-24-2011, 09:59 PM
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
04-24-2011, 11:27 PM
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/journey_to_the_earth%27s_core/58/HISTP/Saturday_April_2_2011/578684/

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

rfeiller
04-25-2011, 09:40 AM
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.

urbanfarmer
04-25-2011, 02:31 PM
I am not familiar with the specifics of bonsai trees, but in general plants need to maintain a ratio of roots to leaf area in order to stay healthy. Also, your assumption that the roots take in water and nutrients at the tips only applies to woody roots and even that is not entirely accurate. You can not take anecdotal evidence to erroneously make large assumptions of biological concepts especially when those concepts have been adequately analyzed decades if not centuries ago...

The currently held theory for how water flows up and throughout a plant was thought up and researched over 110 years ago... Dixon, H; Joly (1894). "On the ascent of sap". Ann. Bot. 8: 468–470.

:cry: Maybe it's just a conflict of personal philosophy, but I desire to teach people the applicable scientific concepts behind aquaponics so they can decide and figure things out for themselves. As the saying goes, if you give a man a fish you feed him for a day, if you teach a man to grow fish in an inexpensive and low maintenance aquaponic system you feed him for life! :lol: