Fertigate Using Pump Npsh

[howto]

Can I pump from the klong and a barrel

at the same time while maintaining an acceptable NPSH?

My rough calcs say I have 3~4 meters NPSH remaining at the intake.

Pump is 1hp, intake pipe is 1.25".

Will this suffice: 15~20cm from the inlet,

tap in a brass valve with 30cm of 3/8" copper line,

then clamp on a hose which goes to the barrel.

I want to empty a medium size black barrel in <30 minutes.

This is for the garden area, flowers, bushes.

Any tips?

[WatersEdge]

Yes,

It will work,

You just can't let air get into the barrel suction line,

when your fertilizer solution is gone.

or you will have to reprime your pump,

by shutting it off and bleeding the air off.

If your pump is self priming,

then it's no big problem....just a momentary inconvenience.

With a few extra valves and pipe fittings,

you can also stir the barrel to dissolve the fertilizer,

Have a look at the similar system that I built,

http://www.thaivisa.com/forum/Fertiliser-Prices-t274809.html

This system is a separate pump, located between the primary pump and the sprinklers.

Depending on what formula fertilizer you use,

there may be insolubles, which will form a fine mud

They will still flow along with the water to the field,

but will not necessarily go immediately to where you want it

and you have to take care to suck them all up with the solution.

[Maizefarmer]

Howto

If you go to the link below you can see an example of a fertigation system I have up and running

http://www.thaivisa.com/forum/Irrigation-t102785.html&hl=pictures&st=50

See the pic in post #74 - at the bottom of the page

Note the 2 pressure gauges on the top horizontal PVC and the ball valve located between them - adjustment of the ball valves adjusts the pressure/flow, forcing a portion of the water to flow through the square 1" u-section underneath, which syphons chemical up from the grey buckets below via a linear hydraulic motor contained in the black plastic linear injector casing that hangs above the buckets. The injector is throttled up/down by adjusting the ball valve on the left hand side down leg of the u bend, hence fertigation rates can be set independantly of flow rates.

For example: you can set the system to deliver say 2 litres of chemical per 10 000 litres of water over say 1 hour. or you can set the system to deliver say 20 litres of chemical per 250 000 litres of water over say 10hrs, or over 5hrs.

This is what is known as a "pressure differential" system/setup and ensures the dilution mix stays proportional irrespective of flow rate over time.

The large diameter short black "tube" on the left hand side of the system is a disc filter with if I recall correctly 160 Mesh discs inside - essential on dripper systems

This system suports a dripper line setup that covers 22rai.

This particular unit feeds dripper lines, but it can be applied equally well to a impact head (sprinkler) setup, though take note of my comments in post #84 regards using pesticide through sprinklers.

PS - on the extreme right hand side of the pic, for those interested, is a small solar panel used to power an electric fence - the pulse generator is contained in the grey lided plastic box on the ground next to the fence

[howto]

Thanks to both WatersEdge and Maizefarmer...

I read your posts.

I am surprised that my search did not bring those up,

(I have not visited the "irrigation" thread in some time).

Anyway your "setups" are far, far larger than my needs.

But one post did mention what I want (but no details).

My garden is only 15x15 Mt.

However in any instance your data helps.

Later I will likely use a disc filter and drip's.

And probably a smaller pump.

Again thanks for your help.

However my question was not answered...

I honestly did not state it totally.

I did read in the "irrigation" thread

that one can do what I want to do...

that is to say "dirt-cheap fertigation".

Simply stated...

is their a ratio 'tween

the main "suction" pipe size

and tapping a pipe into it...

I assume no more than 10~15% of suction pipe I.D.,

of course taking into account the current NPSHA.

So is there a basic ratio in this scenario?

Apologies for being a bother, I can't find this anywhere.

And the math on this fails me.

Ferti pipe too small, long pump running...

too big, may have cavitation.

There must be a balance.

BTW the ferti barrel will be above pump centerline.

Thanks again.

[Maizefarmer]

If your garden is only 15m x 15m do what Watersedge has done - just raise the bulk container (and the bulk container he has are common - can be picked up at scrapyards all over the Thailand), fill it with water, mix the chemical in and irrigate straight from the container. That has to be the simplist way of going about it for a garden 15m x 15m.

if you want to stick with your initial plan, first question is this - what is the flow rate through what you call the main sunction pipe (?) - when you have that you can start making informed calc's regards what diameter to choose for the secondary pipe (i.e. the pipe that is going to tap into it) because that will determine how much suction you have on hand to use. Remember Force is the relationship between mas and area (i.e. the the froce of the water flow and the relationshoip between the 2 pipes ID cross sectional surface areas of water). Then again, if you have a mixing container that is set above the main flow pipe, a thin tube connected to this main pipe at an angle of around 45degrees (pointing towards the direction of flow), with a small ball valve to throttle flow from the chemical container, is all you will need. All this stuff about suction then doesn't have to be calculated at all as with the chemicle mix located higher than main feed pipe to the pump you will have a positive pressure (from the container holding the chemical) flowing into and assisted by the sunction of the water been pulled along the pipe towards the pump.

To test how the chemical mix needs to be throttled with the ball valve so that you get whatever mix is needed to treat the whole garden - go buy some blue food dye from a shop. Mix than into the chemical tank and do a couple of test runs, adjusting the flow rate (through the ball valve) from the raised chemical tank into the pipe that feeds the pump.

The advantage of connecting this all up on the sunction side of the pump is that as water/chemical mix flows through through the pump impellar, it gets nicely mixed in and even better distributed into the flow than it would if it was on the output/positive side of the pump.

KISS - Keep It Simple Stupid - I'm a great believer in keeping things simple & practical - no more complicated than they need to be.

[howto]

Many thanks Maizefarmer

Great info...

WatersEdge, your comments did not go unnoticed.

I am aware of those issues.

a thin tube connected to this main pipe at an angle of around 45degrees (pointing towards the direction of flow),

How do I do that in pvc?

Any advice?

some blue food dye from a shop

That is a great concept...

I was just going to time it with a stopwatch.

(but will change if/when I move to drip,

or a smaller pump, currently it's just a open 3/4" hose).

mix flows through through the pump impellar

and

KISS,

that is what this is all about.

I do not need much, as opposed to so many others.

I Luv the KISS method.

Thought about posting this here or...

in the small garden section...

decided this section is best as there are newbies.

And the info provided is excellent, will help others.

If the admin want's to move this, fine with me.

For now, I will begin to reorganize this garden...

eggplants, basel's, chilies, and tomatoes

into the large paint buckets...

(they take too much space,

there are other places they can go).

Beans will remain in the garden.

Then the rows will be simply leafy veggies.

I read the "makuai" thread...

if eggplant can grow in paint buckets...

so can basel, chilies and tomatoes.

Then lay in drip irrigation/fertigation on those rows.

It may not be big,

but no reason it is not super productive!

[Maizefarmer]

Many thanks Maizefarmer

Great info...

WatersEdge, your comments did not go unnoticed.

I am aware of those issues.

a thin tube connected to this main pipe at an angle of around 45degrees (pointing towards the direction of flow),

How do I do that in pvc?

Any advice?

Buy a t-piece from the hardware store, then heat it up over a flame to bend the vertical part of the T to an angle of around 45degrees - insert the T piece into the main pipe with the obtuse part of the angle pointing towards the pump = make sure the T - piece is whatever the maim pipe diameter is, but the T setcion is a much smaller diameter, and then step it down even more if you can with a balnk endpiece on the end, drill a small hole in that, and silicone in some aquairum air hose from a petshop. In fact while at the petshop also buy a plastic airhose valve and use that as the throttle in the airhose to control the chemical flow fromt he airhose into the main pipe - cheap and cheerfull

some blue food dye from a shop

That is a great concept...

I was just going to time it with a stopwatch.

(but will change if/when I move to drip,

or a smaller pump, currently it's just a open 3/4" hose).

mix flows through through the pump impellar

and

KISS,

that is what this is all about.

I do not need much, as opposed to so many others.

I Luv the KISS method.

Thought about posting this here or...

in the small garden section...

decided this section is best as there are newbies.

And the info provided is excellent, will help others.

If the admin want's to move this, fine with me.

For now, I will begin to reorganize this garden...

eggplants, basel's, chilies, and tomatoes

into the large paint buckets...

(they take too much space,

there are other places they can go).

Beans will remain in the garden.

Then the rows will be simply leafy veggies.

I read the "makuai" thread...

if eggplant can grow in paint buckets...

so can basel, chilies and tomatoes.

Then lay in drip irrigation/fertigation on those rows.

It may not be big,

but no reason it is not super productive!

[howto]

Another great concept Maizefarmer

Before I saw your reply I mused about this...

(we have a flood, get the wife's car out of here,

fix the truck, be ready for Monday, wife goes to work and

the 2 young boys return to school...

it was a busy weekend)

Buy a t-piece from the hardware store, then heat it up over a flame to bend the vertical part of the T to an angle of around 45degrees - insert the T piece into the main pipe with the obtuse part of the angle pointing towards the pump = make sure the T - piece is whatever the maim pipe diameter is, but the T section is a much smaller diameter, and then step it down even more if you can with a blank endpiece on the end, drill a small hole in that, and silicone in some aquarium air hose from a petshop. In fact while at the petshop also buy a plastic airhose valve and use that as the throttle in the airhose to control the chemical flow from the airhose into the main pipe - cheap and cheerfull

I was going to use a common coupling...

I have a vertical floor drill press with a x-y vise...

mount coupling in x-y vise, angle it to 45 degrees...

drill a hole in it, insert hose and silicone...

then mount this on the suction pipe.

I thought of using aquarium hose/valves...

but would rather use

sink/shower/toilet hose (ID, 5/16 or 3/8) and valves.

All common, cheap, a standard size, perhaps more durable.

That would possible drain a barrel in under 30 minutes.

But I do like the concept of heating/bending a T fitting...

and with a 1/2" on the T section, as common hose/valves will fit.

Mount that on the suction pipe...

at 90 or 270 degrees (offset from vertical), to avoid air pockets.

Many thanks again!!!

[rice555]

Hello gentleman, if you like projects fine, an off the shelf 1/2" ventury injector with pick up tube w/filter screen and metering valve is Bt.480. From 1/2" to 2" injectors are cheap and easy to get in LOS, I've got them BKK and Korat. 2" is Bt.1,220.

rice555 ps, not a stock holder of Super Products.

[rice555]

Hello All, sorry for my post #9, it should have been on another thread.

rice555 (having a senior's moment/brain fart)

[howto]

Hello gentleman, if you like projects fine, an off the shelf 1/2" ventury injector with pick up tube w/filter screen and metering valve is Bt.480. From 1/2" to 2" injectors are cheap and easy to get in LOS, I've got them BKK and Korat. 2" is Bt.1,220.

rice555 ps, not a stock holder of Super Products.

Well rice555, brain farts are accepted here!

I line in Pathumtani, Klong 3...

A large irrigation business is close by,

they carry the SuperProducts, and I have their catalog.

Look at that unit previously,

seems it is a output venturi based system...

I've not read good things about them, such as...

"The worst part of using a venturi

or proportional injector is the radical drop in water pressure.

I wasted money on small venturi's - large ones are very expensive.

Venturi's are inaccurate, which is a function of physical properties such as viscosity and temperatures etc...."

and

"not for use in low pressure drip systems, but fine for ordinary hose pressures".

Anyway seems I can do what I need on the cheap.

And it will work on drip (after using a filter).

But thanks for the post!!!

(I'm annoyed,

- this flood,

- can't seem to fix the truck, both headlights are out!

and they have volts, it is not fuses or relays or wires!

and I have a polytechnic in Electronics since '75)

Guess i'll go make some lemonade.

[Maizefarmer]

Howto

Yes - most venturi type systems are hopelessly inaccurate (which is why I pointed out to you the system I have in place - actually, complete overkill for a 15 x 15 garden), but I don't think inaccuarcy is going to be a big deal or problem over a 15m x 15m sized garden.

It's my humble opinion that the Super Products VFI injector will be plenty suitable for your garden.

[howto]

Thank you Maizefarmer...

The Super Products VFI injector is on page 45,

it does not list any specs...

well the price is too high...

and it is a "output" venturi injector...

so my previous comments about them apply.

It breaks my guidelines in every sense.

Seems DIY is easy!

I have chosen to do DIY using NPSH...

(using previous comments), and I will follow that.

DIY is just not hard to do...

and less expensive than that VFI unit,

and the DIY is far more versatile...

seems I can use it on drippers (with a filter).

The point was to drain a 40~50 liter barrel

in under 30 minutes (actually less than 15 minutes)...

that barrel may have EM, any tea or fert,

then continue with (klong) water,

for a remainder 15 minutes to wash it in.

I do not want the pump to run more than 30 minutes.

Just short and to the point with min cost,

following the KISS method.

That VFI injector will (likely) not do that using drippers.

[Maizefarmer]

No - if your using drippers over that small size of area, then no its no good - you are going to have to use some kind of "positive" pressure system if thats the time frame.

Sorry - I didn;t realise this was all about drippers.

PS - any idea of the total volume you will be watering each time?

[rice555]

Hello howto, to quote you from post #13:

"The Super Products VFI injector is on page 45,

it does not list any specs...

!. I have a page from their 2548-2549 catalog that

gives the specks, PM me a @ address and I'll fwd a

copy to you.(I used up my T-V picture limit, other

wise I would post it) From 1/2"-2".

"well the price is too high..."

2. Was that drill press and vise cheap, for the amount

of work it's turned out?

"and it is a "output" venturi injector...

so my previous comments about them apply.

It breaks my guidelines in every sense.

Seems DIY is easy!

I have chosen to do DIY using NPSH...

(using previous comments), and I will follow that.

DIY is just not hard to do...

and less expensive than that VFI unit,

and the DIY is far more versatile...

seems I can use it on drippers (with a filter).

The point was to drain a 40~50 liter barrel

in under 30 minutes (actually less than 15 minutes)...

that barrel may have EM, any tea or fert,

then continue with (klong) water,

for a remainder 15 minutes to wash it in.

I do not want the pump to run more than 30 minutes.

Just short and to the point with min cost,

following the KISS method."

3. I've used my VFI with village water system pressure,

gravity from cement ring's tank 1M higher than the

irrigation lines and with 1", 1/2HP, 2,400L/H pump.

This was with drip tape, S+P's Queen Gil "High Flow"

and with Metzerplas Lin(from Naan Dan) 1.6 L/H, 30cm

spacing. These were from 300ft of tape to 900ft.

S-P's new spray tape 22mm.(08-09 cat. pg 22) 100'

@ 0.8 to 1.2 Bars pressure regulators.

Neta Fim 24-L/H Bubblers, 46 dripers system.

After the VFI, the water mix goes through a Netafim

1" disc filter.(120 mesh)

"That VFI injector will (likely) not do that using drippers."

4. With the pump, I've ran molasses mix through the drip

tapes, the viscosity thicker than most em mixes.

Again I don't tinker, with teas and kee, I open up a 1kg

bag of water soluble fertilizer, which flavor depending

where the plant is in it's growing cycle, follow the directions

on the package for how much fret to how much water, do

a rough mix, start the pump, fill the lines, open the valve

on the VFI and run the pump for 10 min after the the last

of the mix(fert concentrate) gets picked up

If you are using clong water, you might want to read this

from Netafim, for drippers or tapes. Something that should

be read before anyone builds a drip system, large or small.

http://www.netafimusa.com/files/literature...-System-Ops.pdf

Also for more on the real deal. http://Mazzei.com/

If you want the KISS irrigation system: 1. bamboo yoke.

2. 2ea. 10-lt watering cans. 3. elbow grease, strong back

and weak mind.

This method is still alive and well in SEA, China, Africa and

parts of South America.

For injecting fertilizer into this system, you only need a

dipper of sorts, an old can will do.

No pump or electric needed. No dripper's to clog with em,

kee tea or clong water and, keeps you in touch with your

garden.

I'm in touch with my 300 bags and buckets, 3 times a day,

but because of the cost, no yoke and only a single 6-lt

can, can't afford the larger system, but the labors cheap!

rice555

some people like to tinker, some like growing

[howto]

No - if your using drippers over that small size of area, then no its no good - you are going to have to use some kind of "positive" pressure system if thats the time frame.

Sorry - I didn;t realise this was all about drippers.

PS - any idea of the total volume you will be watering each time?

Thanks MF for all your replies...

I should have mentioned that I desired to use drips...

but I did not want to "rehash" that issue as

there are many threads I have read from tv...

especially your pinned makua thread.

There you briefy mentioned the homemade venturi,

but not how to do it, hence this thread.

The output volume ...

Well 8, 15m rows...

13 Naam 10 lit/hour drips per row,

so max 104 drips.

104 * 5 liter = 520 liter in 30 minutes.

Around 17 liter/minute.

Unknown what the pump output is,

but it is far too large for this application.

A 1/3~1/2 hp will suffice (and use a timer).

Perhaps Kirloskar as suggested by you here,

http://www.thaivisa.com/forum/index.php?showtopic=121387

I still have 2~3 months to implement this,

(and still don't know if I want to).

The homemade venturi will work with a hose or this small low flow drip system.

I continue looking at several threads.

Drips and "pump on a timer" can correct several issues:

over-watering, under-watering,

fertigat/pestigate (Karate Zeon)/herbigate.

Thanks again for all the advice.

Cheers.

[howto]

Hello howto, to quote you from post #13:

"The Super Products VFI injector is on page 45,

it does not list any specs...

!. I have a page from their 2548-2549 catalog that

gives the specks, PM me a @ address and I'll fwd a

copy to you.(I used up my T-V picture limit, other

wise I would post it) From 1/2"-2".

>Thanks, wow a 3 year old catalog,

VFI specs are not in the 2008-2009 catalog

it is very close by, I'll get the 2009-2010 catalog.

Thanks I will pm you, soon.

"well the price is too high..."

2. Was that drill press and vise cheap, for the amount

of work it's turned out?

>Yes, cheap China crap, but does well enough,

it's 5+ years old, paid for itself within 6 months.

As well as my multitude of other tools.

I understand your "point", but the math speaks...

VFI - around 490 baht

Home made - <100 baht.

The VFI will not work at low flow rates where

the homemade unit will.

"and it is a "output" venturi injector...

so my previous comments about them apply.

It breaks my guidelines in every sense.

Seems DIY is easy!

I have chosen to do DIY using NPSH...

(using previous comments), and I will follow that.

DIY is just not hard to do...

and less expensive than that VFI unit,

and the DIY is far more versatile...

seems I can use it on drippers (with a filter).

The point was to drain a 40~50 liter barrel

in under 30 minutes (actually less than 15 minutes)...

that barrel may have EM, any tea or fert,

then continue with (klong) water,

for a remainder 15 minutes to wash it in.

I do not want the pump to run more than 30 minutes.

Just short and to the point with min cost,

following the KISS method."

3. I've used my VFI with village water system pressure,

gravity from cement ring's tank 1M higher than the

irrigation lines and with 1", 1/2HP, 2,400L/H pump.

This was with drip tape, S+P's Queen Gil "High Flow"

and with Metzerplas Lin(from Naan Dan) 1.6 L/H, 30cm

spacing. These were from 300ft of tape to 900ft.

S-P's new spray tape 22mm.(08-09 cat. pg 22) 100'

@ 0.8 to 1.2 Bars pressure regulators.

Neta Fim 24-L/H Bubblers, 46 dripers system.

After the VFI, the water mix goes through a Netafim

1" disc filter.(120 mesh)

>Yes it will work with your system

as you have enough flow across the venturi

to initiate the 20% (required) pressure drop so it works.

Please read the previous reply post to Maizefarmer,

there you will see I will only have 17 Lit/min

or .28 lit/sec flow across the VFI venturi.

It simply will not work.

The VFI has it's place, just not here at my place.

The homemade unit is opposite of that...

as it is on the suction side of the pump and

the fert barrel is above pump centerline and

therefore it has a positive head, so

it will work with very low flow rates and

it mixes the fert better.

But in any case, both will not be accurate

as I understand it, in my case I don't care.

"That VFI injector will (likely) not do that using drippers."

4. With the pump, I've ran molasses mix through the drip

tapes, the viscosity thicker than most em mixes.

Again I don't tinker, with teas and kee, I open up a 1kg

bag of water soluble fertilizer, which flavor depending

where the plant is in it's growing cycle, follow the directions

on the package for how much fret to how much water, do

a rough mix, start the pump, fill the lines, open the valve

on the VFI and run the pump for 10 min after the the last

of the mix(fert concentrate) gets picked up

If you are using clong water, you might want to read this

from Netafim, for drippers or tapes. Something that should

be read before anyone builds a drip system, large or small.

http://www.netafimusa.com/files/literature...-System-Ops.pdf

Also for more on the real deal. http://Mazzei.com/

>I should have said...

That VFI injector will (likely) not do that using drippers "at my flow rate".

I have that Netafim doc, I agree it's a good read.

If you want the KISS irrigation system:

1. bamboo yoke.

2. 2ea. 10-lt watering cans.

3. elbow grease, strong back and weak mind.

This method is still alive and well in SEA, China, Africa and

parts of South America.

For injecting fertilizer into this system, you only need a

dipper of sorts, an old can will do.

No pump or electric needed. No dripper's to clog with em,

kee tea or clong water and, keeps you in touch with your

garden.

I'm in touch with my 300 bags and buckets, 3 times a day,

but because of the cost, no yoke and only a single 6-lt

can, can't afford the larger system, but the labors cheap!

rice555

some people like to tinker, some like growing

>You are really funny and I'm so happy to hear

your in touch with your 300 bags and the water can!

Ok, I live 5 Km from Talad Thai.

All veggies and fruits can be bought there

cheaper than I can grow them.

But hey, this garden is not for me.

It is for my wife (of 20 years), the maid and 2 nannies.

I did my part to get it prepped and heavily amended.

15x15 meters, 8 raised beds 1m wide, 1m walk paths.

They have at it.

It's called "keeping the women happy".

Then, they thought I was Nutz at what I did to create it.

But now everyone says it the best garden they have ever seen...

they've never seen such healthy plants or output.

So they learned something (perhaps).

But I have issues with....

well read the previous post back to Maizefarmer.

The maid and nannies are from Esan, each has 20+ rai.

They mono crop rice, only once a year.

This drip irrigation is a learning curve for me...

and will be a learning experience for them (perhaps).

But I think the "Maizefarmer paint bucket method"

will really knock their shoes off.

I tinker and I grow,

I've only 1.75 rai, just don't have the land for commercial.

But I did grow up on a 300 acre farm,

it's been a long time since I drew water up from a well,

and carried it 100 feet to a 1 acre garden.

Thank you for your comments.

Cheers.