NEW NFT (nutrient film technique) SOG SETUP

[repvip]

The pressure bias pump needs to be working against head pressure to develp pressure. The easiest way to see that there is that g head pressure is to use small tubing before every nozzle. Consider the genral formula: Flow = velocity * Area. so Velocity = Flow / area, by decraesing the area (diameter of the pipe/tubes interior) you thereby increase the velocity and therefore the pressure. If your manifold is a larger pipe (increses area) the velocity (therefore pressure) will be lower. With just 25 spray heads you only need to flow at most 25 gph from a 270 gph pump. So you need to decrease the tubing/pipe isze to incrase velocity rather than sure maximium flow. The pump comes with a 3/4" discharge so as to pump up to 270 gph. That means a pipe/tubing area of 0.442 square inches to move 270 gallons per hour as you need to only move roughly one tenth of that amount of water you theoretically need a pipe/tubing of only o.24 inches interior diameter to handle the entire flow. By using a large pipe with the sprayers stuck straight into the pipe you haveb created a high flow low velocity/pressure system. This means the pressure is to low for the sprayers. Using the lengths of small tubing increases the velocity/pressure at the spray heads. It also decreases flow but you need very little flow. I use a simple 0 to 30 psi pressure gage on all my systems to see that the pressure is just below the pumps max of 24 psi.

Thanks very informative.

So.. to get the best head pressure.

With the 25 sprayer example, you are saying 25 individual spray lines at 1/4" would be best, as that is the smallest tubing ensuring highest velocity? Just use a small piece of 3/4" pvc with 25 lines tapped in?, or probably tap T joints and get 2 lines each, but same concept I think.

What about 5 spray lines using 3/8" outer diameter tubing with 5 sprayers each, coming off the 3/4" outlet/manifold. It's a bigger diameter pipe, but there would be less distance...

I guess I'm still thinking in terms of high flow/low pressure pumps.
With high pressure pumps, that can build pressure against enough sprayers (like you said, only need 25gph flow!), I can't see why either situation wouldn't work, and most mist systems are the latter, but if there is a best solution, by all means lay it on me!

Anyway

Gravity feed paint sprayers are only like $20. Air compressors are cheap. Can't you atomize the solution fairly easy using compressed air? Or is this the basis of high pressure aeroponics? It seems like it might be easier, using compressed air to atomize water, rather than pressurizing the water itself. Shit, the more I learn the less I know

 

[repvip]

For the mites buy some Buhach powder. http://www.buhach.com/ It is sold online http://www.solutions.com/jump.jsp?itemType=PRODUCT&itemID=314 and is also sold in sporting goods stores and outdoor and garden centers. It is burnt as a smudge. There are no flames, it just smolders. It's active ingrediants are Pyrethrins. Mixed esters of (+)-trans-chrysanthemic acid and (+)-pyrethroic acid. i.e. a specific type of Chrysanthemum flowers petals ground up. A teaspoon or so is simply placed in/on a non flamable surface like an empty tuna fish can and lit with a match. Seal the room. Do this every few days until no mites return. It can be used up until harvest. It is non harmful to people and is used in a lot in any places for mosquito control. It is considered a must have for life in Alaska.

Hey is there any worry of this being absorbed into the reservoirs and damaging plants or messing pH? The venturi valves could suck the fumes right in.. actually heard a story of a guy who messed up his plants in a similar way with a sulfur burner, but it was air pumps that pumped it into his reservoirs...

 

[fatman7574]

Thanks very informative.

So.. to get the best head pressure.

With the 25 sprayer example, you are saying 25 individual spray lines at 1/4" would be best, as that is the smallest tubing ensuring highest velocity? Just use a small piece of 3/4" pvc with 25 lines tapped in?, or probably tap T joints and get 2 lines each, but same concept I think.

What about 5 spray lines using 3/8" outer diameter tubing with 5 sprayers each, coming off the 3/4" outlet/manifold. It's a bigger diameter pipe, but there would be less distance...

I guess I'm still thinking in terms of high flow/low pressure pumps.
With high pressure pumps, that can build pressure against enough sprayers (like you said, only need 25gph flow!), I can't see why either situation wouldn't work, and most mist systems are the latter, but if there is a best solution, by all means lay it on me!

Anyway

Gravity feed paint sprayers are only like $20. Air compressors are cheap. Can't you atomize the solution fairly easy using compressed air? Or is this the basis of high pressure aeroponics? It seems like it might be easier, using compressed air to atomize water, rather than pressurizing the water itself. Shit, the more I learn the less I know

With lrage pie the pressure is low. There is no height creating resistance so the pump is not going to build up pressure as the sprayers ibeing directly in the large pipe will mean to little rsesiatan asthey let off pressure. However if you use the lengths of small tubing before each sprayer the pressure will already be high due to the pump trying to flow the same an ount of water through the smaller tubing. The only way it can dio this is to pump at a higher velocity/pressure. Look at it this awy: The pump wants to pump the same amount of water regardless of the tubing size. It tries to do this my pumping the water faster through the smaller tubing than it would have to pump it tht rough the larger tubing. With the waters volume flowing through the large pie thr pressure/velocity is low. That means the vlocit/pressure at the spray heads directly in the large pipe is low. That means the sprayers just leak off a small amount of water so the pressure/velocity remains low. With the small diameter tubing pieces running from the main manifold to the sparayers the velocity/prsessure in the tubes is higher so the sprayers pray more water. As the restriction of the small tubing keeps the velocity/pressure high the pumps does pump less water but a high volume is not needed but a high pressure is needed. If you used small tubing for the full length there would be a great variance between the amount sprayed from each tubing.
The approximate length of the the small tubing should be at least 10 times the interior diameter of the manifold pipe. So if it is 3/4" pipe the small tubing should be a minimum of 7.5 inches long.

Air atomix zers are based upon the air being used to create fine droplets of water rather than using high pressure water forced though a small hole. As this can be done with low pressure air it is chaper to run. However the initial investment is usually higher as the nozzles are more expensive and beacuse of reasons of stealth people use indor compressors maening slent compressors. These reatil are 5 to 10 times the cost of a high pressure diaphragm pump used for high pressure aero. The nozzles for the air atomized system with the dapters star at about $40 on eBay or $80 from a retailer, versus $1 for a high pressure Aero sparyer. However there are at least a dozen sizes of air atomizer nozzles avaialble and each ones output volume can be adjusted both through rasing or lower u your reservoir height (head pressure) or adjtsinfg you air pressure. They can also be siphon fed rather than gravity fed. ecah has there own advanatages and disadvantages. The compressures can be readily built by any fair DIY person as the most commonly sold/used ones are really no more than an air condioner compressor with a sight glass to keep an eye on the oil level and a tapped hole with a plug used to add oil.

Basically cut the top of the compressor cover off with a abrasive cut off disk (even a Dremel tool will work), drill two holes and weld on the ring which holds the sight glass lense and weld on the treaded ring for the filler plug. Then weld the top back on. The air conditioner can be bought from sears for $100. Just throw away everything but the compressor. The pressure switch cab be bought on eaby for aboyt $20. The tank can simply be a propane tank purcahes empty. So about $200 for a $600 plus cheap version without the sight glass or oil plug (not advized). A quality retail one (Jun-Air) with the site glass etc will run twice that amount plus shipping.

 

[fatman7574]

Hey is there any worry of this being absorbed into the reservoirs and damaging plants or messing pH? The venturi valves could suck the fumes right in.. actually heard a story of a guy who messed up his plants in a similar way with a sulfur burner, but it was air pumps that pumped it into his reservoirs...

Smoke from ground up Chrysanthemum flower petals? I highly doubt there would be any problems. I have been using Buhach for over 30 years both in my grow rooms and in my homes. At most the only harm would be a extremely small chance of a slight lowering ofyour nutrie pH as all natural esters are acidic. I dusted it directly on to outdoor plants for years without harm. I don't recommend that anyone buy and use the synthesized Pyrethrin spray on garden version. Especially not during the last few weks of budding. It is nasty tasting *hit.

 

[streetlegal]

Hey is there any worry of this being absorbed into the reservoirs and damaging plants or messing pH? The venturi valves could suck the fumes right in.. actually heard a story of a guy who messed up his plants in a similar way with a sulfur burner, but it was air pumps that pumped it into his reservoirs...

RV sup.. u improved on 8 ozcars yet?

 

[repvip]

RV sup.. u improved on 8 ozcars yet?

Nope. It hasn't been long enough..

Thanks again fatman, for answering those questions. You are like macguyver building all sorts of things out of AC units Experience is the key! You remind me of Uncle Ben.

 

[sherriberry]

fatman... i understand what you are saying about pipe size... however, ive grown up around large pnumatic systems since i was a child, and i have to disagree on this...

the only area of interest is the area of the sprayer orfice.

if the pipe was smaller, and restricted flow to the sprayer... that would be one thing...

however...

it does not matter if you have

a 30psi pump
a 3 inch diamerter pipe
and 1 sprayer attached to that pipe

or

a 30 psi pump
a .25 diamerter pipe
and one sprayer attached to that pipe

in both scenarios, the chamber or "pipe" will rise to 30 psi (dictated by the pumps max pressure it can create)

obviously, in both scenarios, the gph of the sprayer is far less than the gph of the pump.. so the system will reach the pumps max psi (of 30 in this case)

both sprayers, in both setups... will each feel the same psi, and thus, flow the same.

if my pipes were too small... that would be one thing... but they arent.

i see no benefit to shrinking the diameter of my pipes.

it would increase the velocity of the flow of nutes inside the pipe, but thats because its a thinner channle that the nutes have to flow through...

but in both scenarios, the psi would be the same at the sprayer head regardless.

only way the psi will drop off is if the pipes are too narrow, and thus restrict flow due to friction tot he sprayer orfice, and thuse reduce pressure felt by the sprayer head.

regardless....

the leaks around my sprayers is the current problem im very sure...

so as far as epoxies go... any ideas?

i hate mixing epoxy

 

[sherriberry]

in labans terms...

making a narrower pipe DOES raise pressure IF there is no restrictive orfice at the end of it (sprayer)

it raises pressure because it restricts flow due to friction (but in our case, we already are restricting flow with the sprayer orfice, so its a mute point)

if we restricted flow BEYOND what the sprayer orfice does via a thinner pipe, i would raise the psi in the pipe, however you would have a psi drop off the further the fluid flows down that restrictive pipe... thus the psi would always be lower at the sprayer head with the restrictive pipe than with the non restrictive pipe

it creates a loss of pressure over distance by using a smaller restrictive pipe.

you cant have too big of a pipe... the pipe is no longer a pipe... it is a chamber due to the fact that it has no exists other than the sprayers.

if the pipe had an open exit the size of the pipes diameter....

...FATMANT IS EXACTLY CORRECT, one would need to restrict the pipes diameter or this exit hole size...

in our systems, we dont have an exit.

pressure is dictated by sprayer orfice size x number of sprayers.

as long as the pump is rated to 240gph, and we dont use more than 240 sprayers,a nd our system has no leaks...

then the system AND ALL THE SPRAYERS will feel 30 psi, if thats what the pump is rated at at 240gph.

make sense?

 

[repvip]

sherri I think this is where different pump types determine the system pressure

i.e. low pressure/high flow pumps will work best with smaller diameter pipes of a large manifold, to get that nice difference in head pressure.

However, like you said, and I alluded to earlier.. a medium pressure pump shouldn't really matter as it will be capable of pressurizing the system (assuming it's not excessively long like 1000' or wtfever) regardless.

It's just the weak pumps that can't maintain pressure.

Have you thought about purple pvc primer and regular PVC cement?

 

[fatman7574]

It is a mag drive pump with a volute (impeller chamber) specifically designed for pumping against a high staic head pressure. With a large pipe likely just a few feet above the pump there is no high pressure developed due to static head. Therefore there needs to be friction head other than just the orifce created friction as that resistantance drop as soon as water strarts going through the orifice so the pumps drops its velocity and pressure. The small tubing resistance remains even when water is flowing making the pump work against a constant friction therefore pumping at a higher velocity as designed. Mag pumps behave differently than a shaft pump. Pressure bias pumps are different than flow bias pumps. For an example with a mag pump if the resistance is too high then the magnet stops turning and the pump motor continues to run. A shaft driven pump would continue to build pressure until it over heats and the motor shuts down. The Iwaki is a mag drive pump. Yes fixing the leaks will help, but it will likely not fix the problem. Mag drive and shaft drive pumps are just not the same. The pressure in a pipe in lengths we are working with increases with a smaller diamter as the velocity increases. The volume of flow decreases not the pressure. With long runs yes the accumalative friction of the smaller pipe would change everything but that is not an issue heare really. The simple Formula Flow = Velocity * Area is sufficient. Your jumping ahead all the way to Bernoulli's principle. Put your thumb part way over the end of a graden hose. The water volume tries to stay the same coming out of the hose. If it stays the same then it is because the velocity has increased. We aree however working with a magnet and a motor which does ano lways deliver a set volume so Bernollis principle does not really apply unless you want to continously adjust the velocity in the equation as motor speed and the manets grasp changes along with volute factors.

 

[sherriberry]

i disagree fatman...

but im not worried if we never agree on this topic because i know you have a ton of other knowledge to offer, so im not going to split hairs over it...

but the entire system... is at 30psi.

IF the entire system was not at 30psi...

say if there was a large hole somewhere...

THEN to get the psi high at each sprayer site, THEN the pipes where the sprayers are connected would need to be of thin diameter.

but if you think that the entire system is not at 30psi already, you are mistaken.

you could hook one of these pumps up to a tank the size of a house...

it would take it a long time...

but eventually the tank the size of the house would become pressurized to 30 psi... as long as the pump is kept on.

volume of the chamber dictates how long it takes to pressurize the chamber.

a chamber the size of a house would take about a day to pressurize... but, it would become 30 psi...

and if you plugged a sprayer into that... it would spray the same as a sparyer hooked into the pipe of the diameter you are talking about.

chamers... are dead ends.

pipes, are pathways... and when the pathway has an open outlet and is not a closed chamber system.. you are entirely correct.

but, im beyond positive of this concept... and if you want to set up a test, or put a wager on it, ill make it worth my while to set up a test...

then we can do it...

but im sorry, in this instance im 100% positive your thinner hose will not increase psi.... the psi is already at the pumps max psi... whatever it is... because the chamber is CLOSED, and not an open system... the only escape is the orfices...

pipe diameter and size is irrelivant.

im positive.

dont post again unless its your paypal account and how much money you wnat to bet

 

[repvip]

i disagree fatman...

but, im beyond positive of this concept... and if you want to set up a test, or put a wager on it, ill make it worth my while to set up a test...

then we can do it...

but im sorry, in this instance im 100% positive your thinner hose will not increase psi.... the psi is already at the pumps max psi... whatever it is... because the chamber is CLOSED, and not an open system... the only escape is the orfices...

pipe diameter and size is irrelivant.

im positive.

dont post again unless its your paypal account and how much money you wnat to bet

Lets just use your setup as a test. I think you are wrong. You are already having pressure problems. You really think fixing those leaks will solve your low pressure problems?

 

[sherriberry]

there is no pressure issue out of the sprayers once i fixed the pvc leaks...

but...

the water is spraying out HARD around the sprayers.. and through them...

so, the leak is a problem only because its going to flood one post more than the others...

as far as certain sprayers not spraying, it was because they were clogged, but i got that taken care of.

so, i got done gluing all the sprayers into the pvc, and come tomorrow once its 100% dry, i will test again, and i think i shouldnt have anymore problems.

 

[streetlegal]

there is no pressure issue out of the sprayers once i fixed the pvc leaks...

but...

the water is spraying out HARD around the sprayers.. and through them...

so, the leak is a problem only because its going to flood one post more than the others...

as far as certain sprayers not spraying, it was because they were clogged, but i got that taken care of.

so, i got done gluing all the sprayers into the pvc, and come tomorrow once its 100% dry, i will test again, and i think i shouldnt have anymore problems.

All this bullshit that ur putting urself through isnt for any real gain.. A zero veg clone plant in any well designed system will always yield about the same give or take a few grams.
Aero/nft low pressure high volume works just as well, its proven. Cut to size, drill some holes some glue, sprayers bam, done in an hour..
This isnt a negative comment as i know building and desiging is fun and an enjoyable part of growing.

 

[sherriberry]

what im putting myself through is not any harder than using the sprayers you are used to... i used them as well...

these sprayers just need a tad of glue added before one puts them in the pipe... big deal...

everything else is the same...

infact, its easier because i only need on pump for up to 100+ sprayers...

and the ez clone sprayers allow too much flow to go by, so the system loses pressure and flow to the furthest sprayers... meaning one would have to add another pump.

im looking forward to getting the hang of this... its identical to the stinkbud setup... just different sprayers, and a different pump... and a lot more posts

 

[sherriberry]

fatman...

that buhach powder...

does one have to have a flame UNDER that tuna can?

or can one just pour it in the can, and light it from the top, and then forget about it?

how often and how much do you use?

thanks bro

 

[repvip]

there is no pressure issue out of the sprayers once i fixed the pvc leaks...

but...

the water is spraying out HARD around the sprayers.. and through them...

so, the leak is a problem only because its going to flood one post more than the others...

as far as certain sprayers not spraying, it was because they were clogged, but i got that taken care of.

so, i got done gluing all the sprayers into the pvc, and come tomorrow once its 100% dry, i will test again, and i think i shouldnt have anymore problems.

That is so great! Fuck physics I don't care anymore. It's all about the pump. I haven't had a low pressure pump (5-6psi or whatever) able to maintain even that low amount of pressure over ~25ft of 1/2"pvc with only 20 sprayers, assuming 25gph each that's only 400gph, and I was using a ~1050gph pump before I just gave up. So I'm really glad to hear that.

All this bullshit that ur putting urself through isnt for any real gain.. A zero veg clone plant in any well designed system will always yield about the same give or take a few grams.
Aero/nft low pressure high volume works just as well, its proven. Cut to size, drill some holes some glue, sprayers bam, done in an hour..
This isnt a negative comment as i know building and desiging is fun and an enjoyable part of growing.

I disagree Every little improvement helps. I think this will make a big difference. Have you seen a true HP rootball? I've never seen anything like it. And I only want half that

 

[streetlegal]

what im putting myself through is not any harder than using the sprayers you are used to... i used them as well...

these sprayers just need a tad of glue added before one puts them in the pipe... big deal...

everything else is the same...

infact, its easier because i only need on pump for up to 100+ sprayers...

and the ez clone sprayers allow too much flow to go by, so the system loses pressure and flow to the furthest sprayers... meaning one would have to add another pump.

im looking forward to getting the hang of this... its identical to the stinkbud setup... just different sprayers, and a different pump... and a lot more posts

cool man.

I disagree Every little improvement helps. I think this will make a big difference. Have you seen a true HP rootball? I've never seen anything like it. And I only want half that

Your a root man RV..I like some root myself.. (although u cant achieve the pom pom root in channels) Like i said i dont think there would be any difference in a well set-up SOG under the same lights etc, ur looking at about a 1oz per plant average..but if u can improve that by grams even, that will make a difference over time no doubt.. I have no problems eating my words if it comes to it tho RV im kinda hungry too, its lunchtime over here

 

[repvip]

Your a root man RV..I like some root myself.. (although u cant achieve the pom pom root in channels) Like i said i dont think there would be any difference in a well set-up SOG under the same lights etc, ur looking at about a 1oz per plant average..but if u can improve that by grams even, that will make a difference over time no doubt.. I have no problems eating my words if it comes to it tho RV im kinda hungry too, its lunchtime over here

Bro, if I was getting 1oz/plant, I'd be getting 2.5lbs every 2 weeks! Instead, I'm averaging 1/4oz/plant. Real world sucks

It's easy to say, a properly built system should work great. I must be doing things horribly wrong! I thought my systems were properly built... Hah, anyway, I will take any improvement I can get!

 

[streetlegal]

Bro, if I was getting 1oz/plant, I'd be getting 2.5lbs every 2 weeks! Instead, I'm averaging 1/4oz/plant. Real world sucks

It's easy to say, a properly built system should work great. I must be doing things horribly wrong! I thought my systems were properly built... Hah, anyway, I will take any improvement I can get!

Well ive averaged round half oz per plant SOG in the real world, some plants more, without co2 (i got co2 coming btw, harvestmaster easi and reg, got a bargain)
Ill start by saying im a fan of ur grow and a fan of urs RV, i think ur a smart dude but i do think something is amiss with ur grow to not be achieving weight.. im far from an expert RV so its just my opinion but i think LIGHTS and secondly genetics are cruelling ur grow..