Help with pump type/size - DTW drip system

[method187]

I am designing a new room and this is my first attempt at a DTW drip system using rockwool cubes.

I will have 2, 3' x 16' tables, with 48 drip sites on each. So a total of 96 sites.

The water will have to run from my reservoir up about 3', then run flat for 16', turn left for 8', and run flat for another 16' to an end plug. Not much elevation to deal with but quite a distance to pressure.

The more I research the more I find people saying typical (say 1000GPH) submersible pumps won't do the trick.

Is there a certain type of pump needed for this style of drip system?

It seems to be quite a bit larger than any DIY examples I can find.

If anyone can shed some light here or recommend a good resource I would really appreciate it.

Thanks for reading.

 

[mango420]

I use a 1200 little giant to supply my 100 site room no problem. These pumps are a bit pricey but I've never burned this one out in the 6 years of continuous use. Gone through a few of the ecoplus ones tho.

 

[Can of Bliss]

Do you have a spec sheet on the drippers?

 

[method187]

Just the generic 5" dripper stakes fed by 1/8 feeder lines. Not sure which size main line to use, somewhere from 1/2"-1" I am guessing.

 

[method187]

Sorry, I meant 1/4" feeder lines.

 

[method187]

I use a 1200 little giant to supply my 100 site room no problem. These pumps are a bit pricey but I've never burned this one out in the 6 years of continuous use. Gone through a few of the ecoplus ones tho.

I think that's the one i'm going to go with.

Do you run 1/2" main line? Or larger?

 

[Hookah79]

Don't skimp on the pump man,you don't want it malfunctioning if you're not on site then you're off trying to fix your grow.

 

[queequeg152]

you need to include your drippers to this discussion.

a diaphragm pump is what you want regardless.... their capacity is fairly limited however, so you need to use small volume emitters for longer irrigation cycles, or fewer emitters per zone.
its up to you.

diaphragm pumps are basically a PD pump... they have a near vertical pump curve. only their amp draw varies drastically with head pressure.

ive gone over this like 1000 times... but the problem with these low volume systems is... there is almost nothing available in a centrifugal pump at these flow rates.

its not untill you hit like 1-2hp that you can reliably find centrifugal pumps that will develop 40+ PSI reliability without issues. problem is these pumps will produce like 60gpm minimum and CANNOT operate at low volumes... centrifugal pumps have a narrower band where they operate well... PD pumps do not.

 

[method187]

Thanks for the responses everyone.

These are the drippers I plan on using

https://www.amazon.ca/gp/product/B00RVAQPM4/ref=ox_sc_act_title_8?smid=A1DP8TS15FKXK4&psc=1

I am still unsure of which pump(s) to go with, but I am considering these

https://www.amazon.ca/gp/product/B000LGA666/ref=ox_sc_act_title_5?smid=A3DWYIK6Y9EEQB&psc=1

Any thoughts or concerns would be greatly appreciated.

 

[queequeg152]

again, thats the wrong pump for this sort of work.

this is probably an open face type centrifugal pump. it will develop good flow rates, but at a small head.

when you try and hook it up to a small collection of these emitters, its going to bog and flow like 1gpm.

you could try and operate the pump with a bypass loop... this would drastically increase the flow rate through the dripper manifold, but this may or may not result in even flow rates across the emitters because each emitter is still a large fraction of the total flow thus resulting in downstream dynamic losses and static losses.

your best bet with a pump like that, with emitters like those, would be with a bypass loop AND valves on each emitter... total pita and not worth fucking with imho.

again at these low flow rates you need to be looking at small diaphragm pumps like this:

https://www.amazon.com/Delavan-Diap...8&qid=1488879072&sr=8-2&keywords=delavan+pump

and small regulated emitters like these:

http://www.greenhousemegastore.com/product/netafim-spray-stake-assembly/dripper-stakes

 

[Speed of green]

again, thats the wrong pump for this sort of work.

this is probably an open face type centrifugal pump. it will develop good flow rates, but at a small head.

when you try and hook it up to a small collection of these emitters, its going to bog and flow like 1gpm.

you could try and operate the pump with a bypass loop... this would drastically increase the flow rate through the dripper manifold, but this may or may not result in even flow rates across the emitters because each emitter is still a large fraction of the total flow thus resulting in downstream dynamic losses and static losses.

your best bet with a pump like that, with emitters like those, would be with a bypass loop AND valves on each emitter... total pita and not worth fucking with imho.

again at these low flow rates you need to be looking at small diaphragm pumps like this:

https://www.amazon.com/Delavan-Diap...8&qid=1488879072&sr=8-2&keywords=delavan+pump

and small regulated emitters like these:

http://www.greenhousemegastore.com/product/netafim-spray-stake-assembly/dripper-stakes

Netafim Plum sprayers and a diaphragm pump are what i use on a 99 drip site greenhouse. This is what you need, high pressure low volume. My 2300gph mag drive wouldn't even pressurize the system.

you will also need a 12V dc power supply for the diaphragm pump.

Queequeg - educated me on this a while back and saved me a a bunch of money and time only having to build it once, you would be wise to do the same.

Also the netafim spray stakes are awesome, cheap, and do not clog easily.

 

[method187]

again, thats the wrong pump for this sort of work.

this is probably an open face type centrifugal pump. it will develop good flow rates, but at a small head.

when you try and hook it up to a small collection of these emitters, its going to bog and flow like 1gpm.

you could try and operate the pump with a bypass loop... this would drastically increase the flow rate through the dripper manifold, but this may or may not result in even flow rates across the emitters because each emitter is still a large fraction of the total flow thus resulting in downstream dynamic losses and static losses.

your best bet with a pump like that, with emitters like those, would be with a bypass loop AND valves on each emitter... total pita and not worth fucking with imho.

again at these low flow rates you need to be looking at small diaphragm pumps like this:

https://www.amazon.com/Delavan-Diap...8&qid=1488879072&sr=8-2&keywords=delavan+pump

and small regulated emitters like these:

http://www.greenhousemegastore.com/product/netafim-spray-stake-assembly/dripper-stakes

So you're saying one of these small pumps will produce enough flow and pressure for 80-100 emitters? Or are you recommending mutiple pumps?

I am completely green to building an irrigation system like this. I've done countless hours of research and you're the first person or resource i've seen that is suggesting a diaphragm pump. I am unsure what a bypass loop is. Google didn't even bring anything up regarding a bypass loop.

What is the difference between these drip stakes you're suggesting and the normal stakes most growers are using?

The setup I am closely emulating is similar to this, except I am draining to waste and not recirculating:

https://www.youtube.com/watch?v=GeQmNoS-tBQ

Sorry for the continuous questions here but I am just trying to understand your recommendation. I am also in Canada so i'm trying to find a comparable product that I can buy/ship from a Canadian retailer or amazon.ca

Thanks again.

 

[queequeg152]

So you're saying one of these small pumps will produce enough flow and pressure for 80-100 emitters? Or are you recommending mutiple pumps?

I am completely green to building an irrigation system like this. I've done countless hours of research and you're the first person or resource i've seen that is suggesting a diaphragm pump. I am unsure what a bypass loop is. Google didn't even bring anything up regarding a bypass loop.

What is the difference between these drip stakes you're suggesting and the normal stakes most growers are using?

The setup I am closely emulating is similar to this, except I am draining to waste and not recirculating:

https://www.youtube.com/watch?v=GeQmNoS-tBQ

Sorry for the continuous questions here but I am just trying to understand your recommendation. I am also in Canada so i'm trying to find a comparable product that I can buy/ship from a Canadian retailer or amazon.ca

Thanks again.

the reason nobody talks about these pumps is because very few people understand hydraulics, and fewer understand pump technolagies.

cannabis folks are accustomed to buying something off a shelf and working with that... well that works well enough for 99% of the systems you might build, but in this case you really need to go further.

i clicked through the video you linked, and all i could see was drip rings? i dont think there was any video of the pump he was using so i cannot comment on that.

regardless... yes a diaphragm pump is a small flow rate pump, but again its the pressure that really matters. yes a diaphragm pump can run 100's, even thousands of emitters... just not all at once. you will need zoning. this is how very large commercial greenhouses irrigate.

when you design an irrigation system, you need to start at the number of irrigation sites and then work backwards through your equipment design.

say you have 100 plants to irrigate and you want to use the netafim 3.3gph (smallest spray stakes i believe).

well thats 5.5 gpm. thats above what a typical diaphragm can deliver, so you cut it into 2 or more zones, and double your irrigation cycle . now you are at 2.75 gpm. easy, done.
you want to use 6.6gph spray stakes? divide it into 3 zones.
thats 3.7gpm. easy.

so yes these small pumps easily handle any number of emitters you would need.

what is the difference between these emitters and yours?

1st, they are a much higher quality i would argue. second, they are pressure compensated, meaning they will maintain the same flow rate regardless if the pressure drops due to elevation changes, or drops in pressue due to long runs of tubing.
3rd they are low flowing, hence you are keeping the pressure drop very low from emitter to emitter.

the emitters you linked are non regulated, they are just an open oriface that sprays water, they have no mechanism to compensate changes in pressure.

 

[queequeg152]

Netafim Plum sprayers and a diaphragm pump are what i use on a 99 drip site greenhouse. This is what you need, high pressure low volume. My 2300gph mag drive wouldn't even pressurize the system.

you will also need a 12V dc power supply for the diaphragm pump.

Queequeg - educated me on this a while back and saved me a a bunch of money and time only having to build it once, you would be wise to do the same.

Also the netafim spray stakes are awesome, cheap, and do not clog easily.

were you the guy i spoke with a while back about running a demand type without an accumulator?
im curious to see how that worked out.

 

[method187]

the reason nobody talks about these pumps is because very few people understand hydraulics, and fewer understand pump technolagies.

cannabis folks are accustomed to buying something off a shelf and working with that... well that works well enough for 99% of the systems you might build, but in this case you really need to go further.

i clicked through the video you linked, and all i could see was drip rings? i dont think there was any video of the pump he was using so i cannot comment on that.

regardless... yes a diaphragm pump is a small flow rate pump, but again its the pressure that really matters. yes a diaphragm pump can run 100's, even thousands of emitters... just not all at once. you will need zoning. this is how very large commercial greenhouses irrigate.

when you design an irrigation system, you need to start at the number of irrigation sites and then work backwards through your equipment design.

say you have 100 plants to irrigate and you want to use the netafim 3.3gph (smallest spray stakes i believe).

well thats 5.5 gpm. thats above what a typical diaphragm can deliver, so you cut it into 2 or more zones, and double your irrigation cycle . now you are at 2.75 gpm. easy, done.
you want to use 6.6gph spray stakes? divide it into 3 zones.
thats 3.7gpm. easy.

so yes these small pumps easily handle any number of emitters you would need.

what is the difference between these emitters and yours?

1st, they are a much higher quality i would argue. second, they are pressure compensated, meaning they will maintain the same flow rate regardless if the pressure drops due to elevation changes, or drops in pressue due to long runs of tubing.
3rd they are low flowing, hence you are keeping the pressure drop very low from emitter to emitter.

the emitters you linked are non regulated, they are just an open oriface that sprays water, they have no mechanism to compensate changes in pressure.

Ok I understand what you're saying.

The only part that isn't making sense to me is the math behind the emitters and pump.

You say "say you have 100 plants to irrigate and you want to use the netafim 3.3gph (smallest spray stakes i believe). well thats 5.5 gpm."

Can you help me understand the math behind this statement?

Also, what i'm essentially going to end up doing is running 2 identical pumps/systems running 54 emitters.

If for example I used 54 of the small netafirm stakes, which pump do you feel would I need?

My room will be broken into 4 tables so I could also adjust and run 4 pumps to 27 emitters if it made more sense.

 

[Can of Bliss]

Ok I understand what you're saying.

The only part that isn't making sense to me is the math behind the emitters and pump.

You say "say you have 100 plants to irrigate and you want to use the netafim 3.3gph (smallest spray stakes i believe). well thats 5.5 gpm."

Can you help me understand the math behind this statement?

Also, what i'm essentially going to end up doing is running 2 identical pumps/systems running 54 emitters.

If for example I used 54 of the small netafirm stakes, which pump do you feel would I need?

My room will be broken into 4 tables so I could also adjust and run 4 pumps to 27 emitters if it made more sense.

3.3gph*100= 330gph

330gph/60minutes in an hour= 5.5gpm

54 3.3gph emitters would be just under 3 gpm
27 would be about 1.5gpm

 

[queequeg152]

Ok I understand what you're saying.

The only part that isn't making sense to me is the math behind the emitters and pump.

You say "say you have 100 plants to irrigate and you want to use the netafim 3.3gph (smallest spray stakes i believe). well thats 5.5 gpm."

Can you help me understand the math behind this statement?

Also, what i'm essentially going to end up doing is running 2 identical pumps/systems running 54 emitters.

If for example I used 54 of the small netafirm stakes, which pump do you feel would I need?

My room will be broken into 4 tables so I could also adjust and run 4 pumps to 27 emitters if it made more sense.

the math is easy.

100 sites each irrigated with a 3.3gph emitter = 100 x 3.3 gph = 330 gallons per hour.

330 gallons per hour divided by 60 minutes = 5.5 gallons per minute.

this is more than a typical diaphragm pump can handle at moderate pressures so you should divide it into two zones.

what is a zone?

a zone is simply a an isolated branch of your irrigation system that is controlled by a solenoid, just like a lawn irrigation system.

how do you control a zone? there are many ways... but what i use is a pissy cheap lawn irrigation timer/controller. it was like 40-50 bucks shipped on ebay. its all beat up and old... and i dont even have the key to lock it, but it works 100% fine.

you can use other controllers, but lawn irrigation controllers are especially convienient because they have a built in 24vac transformer which allows you to use the ultra cheap lawn irrigation solenoids.

look here... though id invite you to buy something off ebay it will be far cheaper.

https://www.sprinklerwarehouse.com/Toro-Timers-Controllers-s/80.htm

the only thing that you need to look out for feature wise... is a controller that has a "master valve", "main valve" or pump relay. this feature is present on probably 70% of irrigation controllers... it basically triggers a pump or master valve (basically a solenoid that feeds a manifold that in turn feeds more soneloids.) like a second before opening the zone solenoids.

all the above being said, you do not need two pumps, but rather one pump and 2 zones.

what pump would i reccomend? it depends on what you can get where ever you live. i like the modulating pumps ... these pumps ramp up and down based on the pressure in the system.
i got mine on ebay for a pittance... but if i had to buy something off the shelf personally i would go with a delevan 4 or 5 gpm DEMAND type diaphragm pump.

these pumps are usually offered as 12vdc, 24vdc or 110vac.

if you get a 12 or 24vdc pump you will need a power supply to run the pump. i use the meanwell 350watt power supplies. they are cheap and reasonably resiliant.
the ONLY thing i do to the power supply is conformal coat it with spray polyurethane. the conformal coating protects the power supply from corrosion due to moisture etc. i keep my rig outside so it might not be necessary in your case.

https://www.amazon.com/CRC-Urethane...coding=UTF8&psc=1&refRID=Q72JA77PS2PHVZR8VW5X

also you need to understand that these pumps will turn them selves on and off based on the pressure switch setting( im talking about demand type pumps).

this means that you need an accumulator to prevent short cycling.

http://www.supplyhouse.com/Amtrol-WX-102-WX-102-141PR1-4-4-Gal-WELL-X-TROL-In-Line-Well-Tank

you can get them at pretty much any plumbing place. they are very common items for anyone with a water well.

you also are going to want a pressure regulator imho... this will regulate the pressure to you emitters down to a set PSI... say 35psi.

the pressure regulator may not be strictly necessary since the emitters are basically tiny little pressure regulators in their own right... but its a good idea none the less.

 

[sheik_yerbouti]

Hey. I'm in Canada as well and just went through this. I just went into a local irrigation supplier as shipping costs end up ruining you up here so I'd do that if ya can.

You can do it fairly simply and uncomplicated. I have 50 plants and 100 emmitters running off the 5gpm Delevan diaphram pump that Queeg linked to earlier. You can get it in a 120v version as well to avoid having to get a dc power supply. It's more expensive but a dc power supply will cost ya $50 anyway and its one less thing to go wrong. Works like a charm with nothing but a check valve, pump running off a timer and y filter. Thats it.

If you go with pc emmiters you may have to put in a return line back to your rez with a ball valve because the pump will cycle on and off if it hits its internal pressure switch limit at about 55psi I believe. Just increase the flow in the return line back to the rez until you get your desired pressure.

Good luck