smppro
Well-Known Member
LOL nobody had to tell me its called common sense, ive grown plants in soil, soiless medium, drip, ebbnflo, dwc, and about to try aero, what all have you tried? Maybe YOU shouldnt base things on what you here.
bubbleponics superior to aeroponics
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LOL nobody had to tell me its called common sense, ive grown plants in soil, soiless medium, drip, ebbnflo, dwc, and about to try aero, what all have you tried? Maybe YOU shouldnt base things on what you here.
I
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Lakes and rivers? Surely you are joking. We are talking about a closed system here, water in a closed container. Here's the most pertinent part from my physics professor friend, "If the temp outside and inside are the same, then it is impossible to get a lower temperature without doing work against the surroundings by the means of a compressor pump, and this of course is the refrigerator principle."So, if I prove moving water is cooler then non moving water I get $100 ???
Sweet ! I'll pm you my paypal addy Smiles.
A still water body absorbs oxygen just as a river or stream does. However, the amount of oxygen it can absorb is related to the depth of the water, the temperature of the water, and the surface area of the lake through which it is absorbing air. The depth of the water in fact has a great deal to do with the overall temperature. Deeper lakes tend to have pockets of lower temperature water.
This has importance. Colder water can hold onto more oxygen. This means that shallower ponds can't normally hold as much oxygen for the fish. Bodies of water such as this may be able to support warm water fish species such as catfish and bluegill, but unable to provide a living solution for cold water fish such as trout.
As a rule, rivers and streams are the almost opposite. Because of the constant flow, moving water naturally absorbs more oxygen than a still body of water. This is true even if the water in the stream or river becomes warm, though there is also a greater chance of the moving water being cooler than in a lake.
The more rapidly flowing the water is, the cooler and more oxygenated it tends to be, which means that it usually supports cold-water species rather than warm water ones. Slow moving rivers are an exception since the water is able to get warmer and doesn't have the same propensity for capturing air for the fish.
So, moving water is cooler then water standing still. You had no other specifications for proof. You owe me $100, thank you !
I suggest you describe the problem fully, show it to any physicist, chemist, engineer, and ask them for an explanation of exactly how an electric submersible pump in a closed system can possibly lower the temperature. Only if the temperature outside is cooler can you do that and then it is just an energy transfer that will eventually be brought into equilibrium, just like the hot coffee will come to room temperature.
The prof also says this,"No, moving water cannot possibly be cooler than still water in a closed container with no outside forces at work. Actually, if water is in motion, then the added kinetic energy will in fact make it warmer. I am referring of course to motion with respect to the reference frame of the walls of the container, as by the pump you mention.
moash
New Member
anybody i know personally that grows uses ebb/flow......
how does ebb/flow require more upkeep?
MostlyCrazy
New Member
Then explain the principle behind evaporative cooling. Is your res ever warmer than the surrounding tempature? If my attic is hotter than my room how does venting the room heat to the attic cool the light?
MostlyCrazy
New Member
E&F relies on the recirculation of the res nuted water. The weak points are at the intake and overflow where plant matter can impede the flow to a great extent thereby limiting the flow which requires constant vigilance of those weak point in addition to the timer needed to maintain the schedule. In the closed airiated res we do not have to deal with those problems and they are easily adjusted for every res change.
RPsmoke420
Active Member
You weren't specific when you made the wager. You wanted proof moving water is cooler. I gave it, and met all your standards. Therefore, you owe me $100 !
(im kidding with you man)Water retains heat. As the day progresses, temps change. As temps warm up in your grow area, temps in the res will also rise. As the day goes on, temps will begin to drop again. Res temps will also drop, but slower. To help speed up the res temp drop, the pump moves water. The moving water cools faster, and will stay closer (temp wise) to the exterior enviroment.
Not once does anyone say moving water will be colder then your grow room. You must have misunderstood, as I just went back to check, maybe I missed it though ? Still water in your res, with lights on, will be warmer then the surrounding air. To help keep the temps down, move the water in the res to better transfer the heat out. Just like in a stagnant room. Still air will heat up and become uncomfortable, but we put a fan on, and it cools down, not by any outside force, but rather simply by moving the air in the room. Moving air is cooler. And yes, fans use electric motors to run, but they still feel good when its hot !!
purpdaddy
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Check my background
I
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By definition there is no evaporation in a closed system. Do you think there is evaporation going on inside your res? Maybe when you open the lid there is a little. Even then it has nothing to do with water being stirred. I guarantee you'll be published if you can show how stirring water in a closed system results in evaporative cooling. You can wet the outside of your tank and put a fan on it and get evaporative cooling. But it would have nothing to do with whether the water inside was being stirred. Maybe (and I've wondered about this) it is even possible to get a fan blowing into the res and create some evaporative cooling. But then it would have to be well vented out and that lets light again. But a moot point since again it has nothing to do with whether the water is stirred.
As for the hot attic - you couldn't vent into it for cooling if it was a passive vent, meaning just an opening for air exchange between the two rooms. Your room would probably get hotter due to the opening. But if you force hot air out, and the air being brought in is cooler, then it works and it doesn't matter where the hotter air was vented to, gone.
MostlyCrazy
New Member
There is also the fact that the temp of the water on the surface is hotter than the water lower in the res. By stiring the mix you introduce cooler water overall and also increase the evaporation rate at the surface by the movement of the water. Probably only helps a degree or two but in the res every degree is important. Think of moving water as the "fan" version of the "air" the roots are getting.
MostlyCrazy
New Member
Does hot air rise?
I
Illegal Smile
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That part is a good argument well made. I have to reject it because, at least for me, I keep grow room temp constant with AC. Also I don't know that the moving water in a box of water adjusts to outside temp changes any faster than still water, just that some people are claiming it does. But admittedly that does not fall under my prof friend's comment because the inside and outside temps are not the same. I don't think I can bore him with another question since I don't want to tell him what I'm really asking.You weren't specific when you made the wager. You wanted proof moving water is cooler. I gave it, and met all your standards. Therefore, you owe me $100 !
Water retains heat. As the day progresses, temps change. As temps warm up in your grow area, temps in the res will also rise. As the day goes on, temps will begin to drop again. Res temps will also drop, but slower. To help speed up the res temp drop, the pump moves water. The moving water cools faster, and will stay closer (temp wise) to the exterior enviroment.
Not once does anyone say moving water will be colder then your grow room. You must have misunderstood, as I just went back to check, maybe I missed it though ? Still water in your res, with lights on, will be warmer then the surrounding air. To help keep the temps down, move the water in the res to better transfer the heat out. Just like in a stagnant room. Still air will heat up and become uncomfortable, but we put a fan on, and it cools down, not by any outside force, but rather simply by moving the air in the room. Moving air is cooler. And yes, fans use electric motors to run, but they still feel good when its hot !!
However, if a res temp were higher than the air temp (never seen that myself) and you wanted to speed it coming to equilibrium, why not turn the lights out and open the res for like 5 min? Then you also get the evaporative cooling mentioned above. Heck, put a fan on it for 5 min. Still unrelated to the movement of the water.
As for the fan, it isn't really changing the temp (unless it is bringing in cooler air from somewhere else). We perspire, it's our natural cooling system. Moving air cools us faster because of (again) the evaporative effect.
I
Illegal Smile
Guest
No, it goes to RIU
. Hot air does rise. It does so because it is less dense, weighs less than the warm air it displaces. it literally floats on warmer air. helium rises even faster, plus has the added advantage of making you talk funny!
MostlyCrazy
New Member
You've never had a res temp higher than ambient room temp? Most have so why not you? So your theory works in an air conditioned room then, right?
MostlyCrazy
New Member
Smile,
What strains have your grown. Which smokes the best? What are some of the problems you had to overcome and how did you do it?
What strains have your grown. Which smokes the best? What are some of the problems you had to overcome and how did you do it?
RPsmoke420
Active Member
I think our big difference is the AC ! I don't have it, so I battle with room temp.
I would bet you, if you put a two identical res totes in the same grow room, one doing the normal BB thing, the other has NOTHING in it, just water and a lid. I would bet the one with nothing would have high water temps. Would be interesting to do, but I don't have the time or space to have an empty tote sitting around !
My pool. My pool water warms up through out the day. Quite a few degrees. When I turn on all the pumps and filters and gadgets in the pool, the water temp does drop.
Also realize, the tote is NOT a sealed unit, so fresh air does come in. Moving water can mix with the new oxygen and cool itself off, just like a river or lake (just a smaller version) and just like a pool !
I must say, you have brought up some good points and have made me think.
Another note, how do you feed baby DWC plants ? You know, before the roots touch the water ? Manual feed ??
I
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You know, I started out reading threads here and believing that the pump made the water cooler just like I believed the feeder tubes made a difference. Then I started questioning that and became persona non grata in a hurry. Just for wondering out loud whether the tubes could be abandoned. That was interesting because I'm used to moving in circles where questioning assumptions is not only tolerated but encouraged. So I started to look into it. I went to my physicist friend on the water and I find it hard to believe he is wrong. I had PM exchanges with other growers and read new stuff. Not everyone thinks drip is necessary. I had resolved to do it by the book one grow but the response to even talking about removing the tubes made me, of course, remove the tubes. I'm no-one's apostle and I won't be told I can't try something new.
So I had three white dwarf seeds left, and I was waiting for OG Kush seeds to come (they have!). I started the three in the SH tote with three airstones and a bigger pump. 6 gal water. I used the SH hydroton and rockwool. The seeds were germinated and had 1 cm taproots. I put in a 4th netpot with hydrton and rockwool but no seed with a cover I could open to check how far up the pot the water was splashing and how wet it was getting the rw. I expected to top feed and was willing to do that. But I found the water moved up well and the rw was staying as wet as I thought it should be. I since gave one of those plants away to a friend. The other two had roots in the water on day 6. I started AN nutes on day 7 (another tip from the DWC folks). I had no idea what the outcome of this would be but I was ready to fail and learn. They seem fine to me. I don't see what feeder tubes would accomplish. They got plenty of water from the beginning. Here's a pic of one on day 9 (9 1/2 actually). They are under 4 42w cfls.
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