Drip help

[Speed of green]

sooo I need some help with my drip setup, I'll explain how everything is hooked up right now and hopefully someone can tell me where I'm going wrong haha.

So the flower room has 2 trays 16'x4' side by side. There is 1" pvc that goes around perimeter of the room in a horseshoe shape. Out of the 1"pvc there are (40) 1/4" drip lines, one drip line runs to each pot. The 1/4" lines are connect to the pvc with top hat grommets. They do not leak.

The system is powered by a 3000 gph submersible pump in a 55gal drum.

The 1" pvc that goes around the perimeter is attached to the wall at a slight angle 1/4" every 10' so that when the pump is shut off the water will drain back through it into the reservoir.

When the pump runs the first pots closest to the pump fill up faster than the pots further away from the pump.


I was thinking of putting a Y on the end of each 1/4" line and 2 drippers on the end of the Y. do you think this would build enough back pressure to make all the drippers drip? I was thinking 2 drippers per pot so in case one clogs.

Pots are 2.5 gal hempy buckets mainly perlite mix, some vermiculite.


Nutrients are jacks hydroponic and calcnit, should I use a pre-filter?

Also maybe this matters, the pump & reservoir are located at the top of the horseshoe and feeds to one side only, if that makes sense.

Thanks for reading I appreciate the help.

Let me know if this is gibberish and I'll just post some pictures haha.

 

[queequeg152]

wrong type of pump for drip irrigation.

you want somethign that can deal with high static pressure/head.

modulating diaphragm pump is what i use. with netafim 3.3gph spray stakes.

 

[Speed of green]

Thanks man, how do those stakes do with clogging? Have you used drip-clean?

Do you know how many Gal per minute/psi I should be shooting for? There are a lot of options, just want to buy the right thing.

Thanks again

 

[Bush Dr]

"When the pump runs the first pots closest to the pump fill up faster than the pots further away from the pump."

Read about hydraulic friction losses in pipes

 

[queequeg152]

Thanks man, how do those stakes do with clogging? Have you used drip-clean?

Do you know how many Gal per minute/psi I should be shooting for? There are a lot of options, just want to buy the right thing.

Thanks again

ive never had one clog but i run drain to waste outdoors with inline mesh filters typical of most drip irrigation setups.

my pump suction also has a very coarse mesh filter.

biggest issue i have is calcium carbonate scaling, but its never clogged an emitter.

the velocity needs to be VERY low inside your irrigation trunk. this prevents deposited sediments and scale from being kicked up and then sucked up into the emitter barbs.

i also put he the barbs on the very top of the pipe. this probably does not account for much.. but its something i do because i always envision sediment causing issues... it never has though.

the velocity should be low like i said... around 1-2 feet per second or less. most agronomists say you can go up to like 5 feet per second... but poly pipe is so cheap, i just take the lower limit.

if you exceed that, just increase the size of the trunk, or split the zone into two trunks or three trunks etc... or split the zone into two zones. or you can go for a big trunk to half or 3/4 laterals if you are going for an enormous system... but such a system would require much more than these tiny diaphragm pumps can handle.

i throw away my poly pipe EVERY season. yes i recover and re use the emitters, but the poly pipe collects a layer of carbonate in the bottom. it gets worse the farther down the trunk you go... as the velocity is the lowest there.

you CAN inject acid into these lines to dissolve the carbonate... but again were talking about something costing 30 cents a foot MAX. its not worth my time.

ive never run drip clean. to be honest i think 90% of the shit they sell at the hydro store is complete bullshit or just outrageously over priced.


at this point all i buy at the hydro store is coco coir and PP grow bags. id love to go back to rock wool slabs some day, but im running peat lite and coco lite right now because its rock bottom cheapest.

i used to inejct chlorine into the nutrient reservoir, but i stopped. the tank requires periodic cleaning due to carbonate scaling. i have found that the frequency of this scale related cleaning is more than the frequency of cleaning due to biological fouling or algae/slime growth. in other words chlorine injection did not offer me any rewards because my tap water is poor quality which forces me to clean regardless.

no i have never had an issue with biological fouling clogging my emitters. to be honest i thought i would owing to my experiance with tropof bluemats, but i just dont. like i said earlier, i cut up my tubes every year and all i ever see is a layer of carbonate at the bottom of the pipes. no algae, nothing but carbonate.

the stakes themselves get caked in white film... carbonate mostly, but these can be cleaned with acid and a bruch. i dont bother cleaning them though. the oriface is so large on these cleaning is pointless, they will not readily clog at the stake... and if they did you can simply pop off the emitter from the micro tubing elbow and install a new one. the stake oriface can also be cleared from the top by pushing a pin down the barb that accepts the micro tubing.

if i ever went to RO water i would seriously reconsider chlorine injection but right now its not worth my time and effort.
im actually re building my fertigation rig right now in order to get it onto a much smaller pipe rack. i WILL include an injection site for chlorine, but it will be blanked off for the reasons i mentioned above. its just there should the need arise elsewhere.

 

[queequeg152]

"When the pump runs the first pots closest to the pump fill up faster than the pots further away from the pump."

Read about hydraulic friction losses in pipes

its unlikely to be solely related to friction losses... not unless hes using extreemly small diameter piping.


the problem is his pump is not designed to develop any pressure at these VERY low flow rates.

at these low flows, the water being diverted out through the emitter tubing is a large fraction of the total flow rate. being that the diameter of the pipe remains the same... the velocity drops after each emitter and so does the total pressure.

you can regain the velocity pressure lost by reducing the diameter of the pipe, but this is not duct work we are talking about. pipe is much too granular in sizes for this to be possible.

this is not hydraulic friction(though the system WILL have some), but rather the natural result of fluid flows being allowed to find their own equilibrium.

this is no different than allowing a fire hydrant to flow out onto a perfectly flat street in one direction with gutters every 100' or so.

obiviously friction plays a factor, but the biggest reason for asymentrical flow is the fact that its velocity is decreasing naturally as more and more water is draining from the overall flow.

now imagine if that street were flooded 20' high and moving at a few feet per second.

the velocity after each drain will decrease, so will the static pressure/head pressure, however the reduction will be so small as to matter very very little to the subsequent drain.

all gutters will appear to flow evenly because there is such an excess of pressure and flow.

if you ever look up pump curves from a particular manufacturer for various impeller diameters and HP motores etc... you will see that they only give you curves for flow rates and heads in a narrow range... thats because almost no centrifugal pump is able to run properly at all flow rates under its theoretical max... kinda like rocket engines, its very difficult to provide real 0-100% flow rates for any impeller. its usually like 60-100% or even less maby.

the pressrure developed by a pump is mostly funciton of the velocity of the fluid leaving the pump casing. the velocity of the fluid is a function of RPM, viscosity, impeller diameter, volute size, torque etc.
water has momentum like anything else, so more velocity = more momentum = more pressure. when your pump is discharging water at a high velocity, it can do more work than it could at a lower velocity.

a small open faced centrifugal impeller like his developes higher flow and low heads because the water being thrown out radially by the simple impeller is not forcing the water to accelerate much. there is also alot of flow bypassing the impeller, and in order to maintain a high flow rate, the pump casing/volute is probably fairly large in relation to the impeller diameter in order to keep friction losses low.

as a result you get a decent mass flow rate, but at very low pressures.
compare that to something like a large diameter closed face reducing impeller with near radial vanes.. think of a pool booster pump used for cleaning equipment.

with the above impeller, as you increase the static pressure on the pump discharge, yes the over all flow rate reduces, but the flow rate reduction is less dramatic because the discharge flow has MUCH more kinetic energy or velocity so it can basically push through all the shitty staic pressure. there is also less flow bypassing the vanes and slowing down the discharge velocity.

the shitty aquarium pump, when presented with static pressure basically cannot push the water at a fast enough velocity to over come it, and the water cannot get out of its own way fast enough. at this point the pump rpm is probably slowing as a result of low torque as well.

ironically, if one were to allow enough flow to bypass the high static pressure environment, and return back to the pump suction, you could probably improve the pressure to some extent.

its counter intuitive, but allowing a bypass flow will allow the pump to operate at a flow rate and rpm that develops MORE pressure than if you force it to work ONLY against the high static pressure.

if you dont believe me, take any shitty fountain pump and block a portion of its dircharge, and then watch the height of its free discharge.

to a certain point, blocking the discharge will increase the static pressure, and increase the velocity pressure allowing the flow to go higher and higher into the air... however past a certain point the flow will start dropping viciously. if the pump has decent torque figrues it might keep its pressure high, but if it does not, the pressure too will fall and the pump will sound like shit i bet.

 

[Speed of green]

Thanks man, learning a lot more about pumps than i ever thought i would. so I've narrowed in on a diaphragm pump thats 2.2 gpm and 70psi got the drip stakes ordered, ill post back with some details once its all up and running.

Thanks again.

 

[queequeg152]

Thanks man, learning a lot more about pumps than i ever thought i would. so I've narrowed in on a diaphragm pump thats 2.2 gpm and 70psi got the drip stakes ordered, ill post back with some details once its all up and running.

Thanks again.

good luck. i assume this is a non modulating pump?

i hope you know that this pump may or may not short cycle... running up into its internal pressure switch, then shutting off and rapidly turning back on.

if this happens you will need to run out and get a small accumulator and pressure regulator.

this setup will essentially buffer a volume of water behind the pressure regulator such that the pump can run for a minute or two then shut off for 30 seconds or so.
this will greatly prolong the life of the pump.

be aware that the accumulator will continue to drain after the pump is switched off, so size it appropriately or install a solenoid after the regulator and get what ever size accumulator you want.

what a modulating pump does, is throttle its rpm based on the pressure the pump senses. it removes the need for a pressure regulator and accumulator.
its not perfect, but its good enough to run faucets and showers and shit inside boats and RV's. thats what they were designed for.

 

[OG Tree Grower]

Quee, as always you covered this in a much more technical sense than I could have. But there are much simpler and cheaper solutions

Any drip system I have ran was with jet pumps or submersibles depending on how many emitters were ran.
1-Always run your lines in a loop, so tee off the main and build a circle around the plants
2- use orbit pressure compensating dripers

Or what I eventually did was ditch the dripers all together, just stake the spegitti line to media and run your pump on a timer accordingly.
You will get better growth rates with the extra oxygen this method provides

Yes running two dripers is a good idea if your not there daily, as long as your media can from it off fast enough

Pretty much everything else will be solved by running your lines in a loop to create equal pressure, if your last lines don't have enough flow and your first lines have to much you and add little valves to the 1/4"" lines to regulate it but if it's drastic then a larger pump will fix that

Sm-90 helps a lot with any drip or sprayer system

Yes always always run a filter. Cheape 3/4" pvc strainer is fine

Don't use any additives that has chunks or particals floating in it

 

[queequeg152]

the problem with jet pumps is they dont run well at low volumes.

strapping a jet pump to somthign like a 100gph drip trunk line is like straping a jet engine to a radio flyer.

you just dont need that much power. a tiny diaphragm pump will work up to around 5gpm.

a sub pump? sub pumps usually are very high bypass but it depends on the impeller type.

they do develop decent head, but again its the wrong sort of pump for this. too much power.

running shit in a circle will help, and i think he said he did that.
but again his problem is a grossly mis matched pump.

i dont see why you would ever run a drip line without PC emitters?

even with fucking.... dutch buckets you dont need a huge flow of water.

the only time you need flows of water like that... is with systems the rely on dissolved oxygen.

peat lite is like 80% pore space? rockwool is like 90%+ pore space. all these soilless low bulk density mediums have VERY good oxygen permeability, very low perched water tables, and very low tensions. you just DO NOT need excess water.

you want a small flow of water such that the fertilizer solution is not displacing air inside the medium. even in pure perlite medium( very low water holding), you dont need a huge flow, just more irrigation cycles.

perlite bags are quite popular in some countries still and they use EXACTLY the same setup as the rockwool greenhouses.

i run peat lite and coco-lite bags though, irrigating as many as 6 times a day and once at night just before the sun comes up. it works very well so long as you monitor the runoff volumes properly.

 

[OG Tree Grower]

Emitters are a pita , without them you can deliver the same amount of water on a plung type of irrigation similar to ppk, it has nothing to do with Disolved oxygen. You don't need that much water that's why I mentioned to run the pump on a timer accordingly, 15-30 second bursts every so often depending on media.

He is ran his feed line in a horse shoe only feeding one end. That's where the problem lies

I do enjoy strapping jet engines to radio flyers but that's not the case here. you can size the pump accordingly especially if you have pressure compensating drippers and always run your lines in a loop , when I referred to the jet pump that was a 24k grow with 768 dripers.
I grew up building g this stuff from home hard wear parts and always made it work one way or another.

It's just another option that's almost free with the gear he has, rather than new pump , possible accumulator and pressure switch . Obviously your way will work flawlessly and has a better purposed pump.

 

[queequeg152]

emitters are not a pita? what problem do you have with them? they work very well in my experiance.

running shit without emitters IS more of a pita imo becuse you are never going to be 100% balanced flow. even set up properly they are going to vary so some extent. if you are running drain to waste, this makes all the difference in the world when you are trying to maintain an elevated root zone ec.

believe it or not. you can infact run 768 drippers on a very small pump like i proposed.

i only use 3 zones out of my irrigation controller. it has 8 i believe, 12 if you buy the expansion thing, but its been discontinued.

with 6 zones thats only like 128 emitters. with 2- 1gph arrow drippers one each side thats only 4gpm per zone.

also running a pump on such short cycles is not a good idea. you really shoud install an accumulator sized to allow the pump to run atelast a minute.

you are assuming that simply looping his trunk is going to solve these problems. how do you even know that? looping would maby half the static pressure loss. depending on how the pump is built that may have little effect.

 

[OG Tree Grower]

I use organic material and b-1, emitters eventually plug. But it was never that bad, I just found better ways to accomplish the same things.

I disagree that it's hard on a pump to run short on cycles. Yes the pump needs 60 seconds off. But on cycles have never seemed to shorten my pump life by any noticeable amount

I know that will solve his problem because I ran lots of systems like the one he build.

You don't need 100% balanced flow if your media drains properly. Pretty hard to overwater hydro ton or RW if drainage is set up right , but it's easy to get balanced flow, make sure all your spegitti lines are the same length so friction is equal and run your feed line in a loop and there your done.

I do believe that you could run 768 drippers on a smaller pump but like I said back then all I had was home hard wear , no city near by, no internet. But none the less the plants got the water they needed

Edit- one thing I forgot to mention about the jet pump or hugely oversized submersible, that relates to some of the technical aspect quee stated about head pressure and volume , was running the jet pump at lower volumes. This is easily solved by having a valve on your main feed line before the loop. You can regulate this back to the res and oxygenate your res and keep the pump working within its limits. ( just listen to it)

 

[Dropped Cat]

This is very good, informative thread.

I have been setting up a 24 site system for a
small grow cabinet, and have decided to use
emitters for a two minute cycle, amount of cycles
to be tested.

The plants are in 16 ounce coco, drain to waste.

Doing bench testing prior to installation, I want to
water these plants automatically for 5-7 days.

When I am satisfied with the bench testing I will
make the install to the cabinet and post results.

Hand water everyday is okay, but it would make
me very happy to automate.

Great thread, subbed.

 

[queequeg152]

I use organic material and b-1, emitters eventually plug. But it was never that bad, I just found better ways to accomplish the same things.

I disagree that it's hard on a pump to run short on cycles. Yes the pump needs 60 seconds off. But on cycles have never seemed to shorten my pump life by any noticeable amount

I know that will solve his problem because I ran lots of systems like the one he build.

You don't need 100% balanced flow if your media drains properly. Pretty hard to overwater hydro ton or RW if drainage is set up right , but it's easy to get balanced flow, make sure all your spegitti lines are the same length so friction is equal and run your feed line in a loop and there your done.

I do believe that you could run 768 drippers on a smaller pump but like I said back then all I had was home hard wear , no city near by, no internet. But none the less the plants got the water they needed

Edit- one thing I forgot to mention about the jet pump or hugely oversized submersible, that relates to some of the technical aspect quee stated about head pressure and volume , was running the jet pump at lower volumes. This is easily solved by having a valve on your main feed line before the loop. You can regulate this back to the res and oxygenate your res and keep the pump working within its limits. ( just listen to it)

dude read any pump handbook. short cycling DOES effect pump wearing.

i design shitty little waste water treatment plants amongst other things. the little pissy 1/2hp goulds i spec for the reclaimed process water clearly outlines that the pump should not be cycled on and off more than something like 2 minutes on and a minute off or some shit like that. thats the closest pump to something you would use in an irrigation system.

these requirements are to protect shit like the pump capacitors, start clutch( if its a start run cap), wear rings, motor windings, etc.

they make these requirements because otherwise you could easily kill the pump before the warranty is up.

will a pump last forever? no. but short cycling it will mean you are going to be replacing parts and shit more frequently for no good fucking reason.

now some pumps basically dont care how often you cycle them. solenoid pumps... peristaltic pumps... maby the shitty little mag drive pumps that dont have caps? idk.

but a pump start is always hard on the pump itself. the day to day beating they take is probably 90% from running all day long, but still. why fucking wear out a pump any faster than you have to? a fucking accumulator is like 100 bucks.

if you are pumping organic shit then yea. i guess you cannot use emitters.

you an i apparently have very different systems. excess runoff is wasted money, and root zone ec is most important to me as it encourages less vegitative growth and better fruit setting.

when the ec drops below 3 or so my toms start shitting out new growth everywhere. suckers, and strong curly new growth.

getting too much runoff ruins everything. runoff control is paramount in commercial greenhouse systems.

 

[OG Tree Grower]

Quee, I agree 100% your way has a purposed pump and is better for what you describe. Your pump may even last longer than mine but seriously

Jet pumps and sumps are all a hydro grower needs for the most part, there simple , cheap and easy to fix, they seem to wear out every 3-4 grows , doesn't matter if I run continuous 24/7 or short cycle on times.

There 80-140 bucks and I always have a spare on hand.

I have burnt pumps on short cycle off times( Ro boost pump with a huge res that has to much surface area for the float to work right) it happened almost overnight.

I never ran a drain to waste system so your right there . I have always recirculated . I thought speed was recirc?

 

[queequeg152]

Quee, I agree 100% your way has a purposed pump and is better for what you describe. Your pump may even last longer than mine but seriously

Jet pumps and sumps are all a hydro grower needs for the most part, there simple , cheap and easy to fix, they seem to wear out every 3-4 grows , doesn't matter if I run continuous 24/7 or short cycle on times.

There 80-140 bucks and I always have a spare on hand.

I have burnt pumps on short cycle off times( Ro boost pump with a huge res that has to much surface area for the float to work right) it happened almost overnight.

I never ran a drain to waste system so your right there . I have always recirculated . I thought speed was recirc?

it saddens me that you guys ruin pumps every 3-4 grows. lol what pumps are you buying? home depot shit?

as a tom grower... 140 bucks is alot of money. a pump should last years and years and years... even grinder pumps or lift station pumps can last 20 years with parts and service.

check ebay for a second hand goulds or berkley pump. replacable parts, and more importantly.. SERVICEABILITY.

Berkleys are mad expensive new, but who knows, you might find something around 200 bucks from a golf course or some shit like that.

 

[OG Tree Grower]

Quee. Yup straight off the shelf home depo everbuilt /power fist crap. Easily replaceable

You gotta remember most of the stuff you take for granted goes over most people's heads, sometime I have a hard time following you to be totally honest.

I do have access to some different style diaphragm pumps at work but I don't like mixing the two businesses for obvious reasons.

I have always replaced piping , bulbs, filters,Mylar ect every 3-4 grows so I never thought much of having a pump replaced at that time too. If it was monthly I would have to change something but I never thought it was an issue.


What pump would you use to run a 36 sprayer , 12 drip ring .lo pressure areo system? Return rate of about 7 gpm right now with everything on, when you shut off the dripping in flower the return rate is about 5 gpm

 

[queequeg152]

Quee. Yup straight off the shelf home depo everbuilt /power fist crap. Easily replaceable

You gotta remember most of the stuff you take for granted goes over most people's heads, sometime I have a hard time following you to be totally honest.

I do have access to some different style diaphragm pumps at work but I don't like mixing the two businesses for obvious reasons.

I have always replaced piping , bulbs, filters,Mylar ect every 3-4 grows so I never thought much of having a pump replaced at that time too. If it was monthly I would have to change something but I never thought it was an issue.


What pump would you use to run a 36 sprayer , 12 drip ring .lo pressure areo system? Return rate of about 7 gpm right now with everything on, when you shut off the dripping in flower the return rate is about 5 gpm

this is clean water?

what pressure do you need to develop at 7gpm?

im assuming pressure is fairly low... anyway thats right in the range of somethign like a low hp iwaki pump or something like that.

problem with iwaki pumps is they are very costly. they are highly sought after by the aquarium folks so even the used market is pricey.

they are sought after though, because they are very reliable good quality pumps that are SERVICEABLE. i have 2 of their smallest coke can sized pumps, very good quality but not really rated for outdoors use. they are too small anyway.

if you have very low heads then you could even get a small circulation pump. these are very high end pumps meant to run for years and years on end.

http://www.hottubwarehouse.com/lain...nES5is51s0VMtFFICCobDMiM_onGbYFIeIaAtEs8P8HAQ

if you need higher pressures you could just get a 1/4hp - 1/3 hp end suction centrifugal pump off ebay or where ever.

if you need VERY high pressures you might look for a large procon pump. though the big ones will be very costly, however they can run up to like 300psi if i recall correctly. they are used in alot of modular commercial scale RO units.

dont buy shit from home depot. all the pumps ive seen there are plastic shit that you cannot service. get somethign from a decent company that actually sells parts kits.