How will Nitric Acid affect my Fertigation Nitrogen level?

[DumbFalang]

I have a Tank A and Tank B system for fertigation and my A tank contains 3kg of Calcium Nitrate. Problem was, I found my water had a pH of 7.8 and I have had to add 4.5 litres of Nitric Acid to reduce the pH to the disired level of pH6.

 

I wasn't sure how to split the acid, so I split it 50/50 between tanks A and B. Is that OK?

 

My main concern is whether adding the Nitric Acid increases the amount of Nitrogen in my cocktail and how much I should reduce my Calcium Nitrate. I reduced it to 2.5kg last time but I am about  to do a new mix and I thought I'd seek advice from the experts ;-)

[Hereinthailand]

hmm hard to understand your idea here, do you have a separate water tank from your a-b tanks ? Also 4,5 litres is a lot of acid unless it is very weak. Systems I have seen have the a-b solutions injected into a reservoir then that goes to the plants with a ph meter always monitoring values. They say nitric is good for growth with a switch to phosphoric for flowering. Not an expert by any means.

[DumbFalang]

I found from research that 100ml of Nitric acid contains 18.5mg of Nitrogen. From that, I have been able to adjust my mix accordingly ;-)

 

Anyone know where I can get Phosphoric or Sulphuric acid? - preferably around Chiang Mai

[Scoop1]

Hi all, DumbFarang, you need to find out what percentage  of Nitrogen is in the Nitric Acid and how much water are you diluting it in and also what are the percentages of the Calcium Nitrate and what other fertilizer salts are you adding to the mix, Part A and Part B

Cheers

Scoop

[Hereinthailand]

If you want to use sulfuric just go buy some new battery acid and dilute it down with water, if they have 33% its already diluted. Remember always add acid to the water.

[DumbFalang]

My current setup is two 100 litre stock tanks and two 500 litre 'mixing' tanks. I fill the two mixing tanks from the well with water that is currently around 7.2pH. I then manually scoop 2 litres from each stock tank and add it to the mixing tanks. At a pH above 6, my plants were not going to absorb all of the nutrients so I decided I needed to reduce the pH of the water.

 

What I did was to fill a 500 litre tank with water and keep adding Nitric Acid until the pH reached 5.8. I multiplied the amount by 100 to match the concentration of my fertilizer mix in the stock tanks with the understanding that when I add my usual two litres of stock water, the amount of acid would reduce the pH to the desired level.

 

To my surprise, when I tested the pH of the water in the mixing tank after adding the stock water, the pH was 6.8. The only assumption I could make was that one or more of the fertilizers was raising the pH. Now I don't know whether I need to add more acid or leave things as they are?

 

I have Calcium Nitrate and Potassium Nitrate in tank A. I have Potassium Nitrate, Magnesium Sulphate and Mono Ammonium Phosphate in tank B. The concentration of the Nitric Acid is 68% (serious stuff).

 

I don't like the idea of adding so much acid to my stock tanks so I'd appreciate any suggestions you guys have on improving my setup or correcting my mistakes.

Edited December 29, 2016 by DumbFalang
Forgot important info

[rice555]

I haven't used any up/down to adjust my pH from Well water here in Korat

and haven't had any problems. I was under the assumption that you adjusted

the pH after you added the A-B(& C in my case) to the water, not before.

rice555

[Hereinthailand]

Yes you add ph adjust to the mix not the water as your nutrients will change ph levels. I like a ph of 6-6.5 your plants will never uptake all the nutrients anyway. You should also give your nutrients some mixing with a re circulation pump for a day to let things balance out, then check ph each day as it will change as its working.

[Scoop1]

Good morning all, dumbfarang, can you tell me what you are trying to grow and how you are trying to grow it, after reading your post I am a little confused about the way you are going about it, is it a Hydroponic system or an Aquaponic system ?, normally you would make up a balanced Hydroponic Nutrient Concentrate { say 10 litres of Part A and Part B } and add what ever amount of the concentrates that are needed to the supply tank to get to the desired EC in the Working Strength Solution , as with the Ph. if your Nutrient Formula is properly balanced and your water supply is around the Ph. 7.0 mark, your Working Strength Nutrient Solution will settle around Ph. 5.8 - 6.2 which is fine, I also noticed there are no Iron or Micro Elements mentioned in the mix, and you cant grow plants without them.

Cheers

Scoop

[Scoop1]

Hi all, dumbfarang,  10 grams of Nitric Acid at 62% N at a dilution rate of 1-100 will supply 6.2 ppm of Nitrogen

Cheers

Scoop

[JungleBiker]

On 30 December 2016 at 6:36 AM, Scoop1 said:

 I also noticed there are no Iron or Micro Elements mentioned in the mix, and you cant grow plants without them.

 

 

I think DF is irrigating (or should I say fertigating or nutrigating) strawberries in the soil. If so, what I'm wondering is, what is the pH of the soil? If the soil is acid, then perhaps applying a nutrient solution with a high pH is not a bad thing and perhaps the nitric acid may not be useful? 

[DumbFalang]

Correct - I am growing Strawberries in soil. I do add trace elements to my stock tanks. This is the first crop grown in the field for several years so although I think many trace elements may be present, it was a rush project and I didn't have time to get the soil tested. I understand that everything is guesswork without soil tests, but that's the way it is at the moment.

 

We are one of the very few farms in Samoeng that have actually been able to produce fruit this year, so I know I am quite close to getting things right. I am following guidelines on fertigation from Australia and USA but none of my research came across the topic of adjusting the pH of water.

 

I found some Phosphoric Acid (98%) so I'm going to do some testing and come back to you guys for advice. The Strawberries are just coming to the end of their first harvest so we will be stripping the plants down and preparing them for the second and main harvest in February. I think I'll stick with Nitric until the first flowers appear.

 

Just as a side note, a few of my English Strawberry varieties are currently fruiting and two varieties in particular are very exciting. The fruit is huge already and we are eagerly awaiting the first taste test in a few days time. First Raspberry ripe today too but no signs of anything from my Blackberries.

[rice555]

1 hour ago, DumbFalang said:

Correct - I am growing Strawberries in soil. I do add trace elements to my stock tanks. This is the first crop grown in the field for several years so although I think many trace elements may be present, it was a rush project and I didn't have time to get the soil tested. I understand that everything is guesswork without soil tests, but that's the way it is at the moment.

 

We are one of the very few farms in Samoeng that have actually been able to produce fruit this year, so I know I am quite close to getting things right. I am following guidelines on fertigation from Australia and USA but none of my research came across the topic of adjusting the pH of water.

 

I found some Phosphoric Acid (98%) so I'm going to do some testing and come back to you guys for advice. The Strawberries are just coming to the end of their first harvest so we will be stripping the plants down and preparing them for the second and main harvest in February. I think I'll stick with Nitric until the first flowers appear.

 

Just as a side note, a few of my English Strawberry varieties are currently fruiting and two varieties in particular are very exciting. The fruit is huge already and we are eagerly awaiting the first taste test in a few days time. First Raspberry ripe today too but no signs of anything from my Blackberries.

 

Is your soil in pots/bags or dirt beds and what is the soil pH?

rice555

[DumbFalang]

Dirt beds....

but unfortunately I don't know the pH of the soil.

 

Also, I discovered it is Sulfuric Acid we have just bought and not Phosphoric Acid. Got a problem with parts of the the drip tape clogging up so just about to go clean everything.

[Hereinthailand]

very nice setup, do you have screen mesh drip filters installed to help prevent clogging ? I wouldnt worry about your acid type too much as long as it gets your ph down. I would think about doing a good water flush every so often to help stop any salt buildup from your nutrients since you are doing soil media growing. Be careful and wear safety equipment using that strong % acid, you might want to dilute it down to make it easier to use, I use a dilute nitric mix from HiGreen Hydro in bkk, 120 ml for 30 ltr mix drops my ph 2 points. Here is a quick and dirty way to get an idea of your soil ph, http://preparednessmama.com/testing-your-soil-ph-without-a-kit/

[JungleBiker]

On 1 January 2017 at 0:15 PM, DumbFalang said:

 Got a problem with parts of the the drip tape clogging up so just about to go clean everything.

 

Are your emitters facing downwards, i.e. on the bottom side of the drip tape?

It's better to have them on the top, to reduce clogging. Dirt will tend to be on the bottom of the tape and you can flush it out sometimes, by opening up the ends. 

[DumbFalang]

I do have filters but not too sure of the type. Flushed yesterday and will now get the staff to do it on a weekly basis. We found algae build up in the mixing tank and the problem was we did not cut our plastic down the middle of the rows like most others do, so we could not see the drip tape. I have now cut down the middle and exposed the tape so I can see what's going on. The emitters are facing upwards. Some had algae around them and a small number were blocked.

 

Basically - all beginners mistakes that we are working to fix and luckily not too much damage done (just a few dry, half dead plants).

[JungleBiker]

Cutting the plastic mulch down the middle is not normal practice if the drip system is well designed and managed, and the equipment is good quality. 

If you put the 2 words strawberry plasticulture into Google, then click on images, I doubt you will find a photo showing a slit down the middle of the plastic mulch. 

In order to save money, I myself have made mistakes. Just yesterday, I started to rip out a few hundred metres of blocked drip tape!

Anyone can go to Do Home or Global, buy pipes, tape, filters, etc, stick them together and get the water flowing. 

But there's more to it than that, and I'm not an irrigation engineer. 

Next week a guy from Netafim will come. I'm hoping he'll put me right. 

 

Regarding the algae, it needs light to grow, so perhaps you could cover your mixing tank to keep light out.

 

 

[DumbFalang]

JungleBiker nailed it with the algae - the tanks are not properly protected from the light. A pump room is on my growing list of things to do. It will be interesting to find out what you learn from Netafim.

 

I screwed up again. I added Sulfuric to tank A..... with my Calcium Nitrate . Anyway, I've decided I don't want to use Sulfuric because at 98% - it's a serious accident waiting to happen. I'm going back to Nitric and need help to balance my cocktail.

 

Here is what is in my Calcium Nitrate...

 

 

In a perfect world where my well water had a pH of 6, I would add 3000g of Calcium Nitrate to my A tank. In the real world, my well water has a pH of 7.4 and I need to add approx 6-7 litres of Nitric Acid to reduce the pH to an acceptable level. I have learned from you guys that the irrigation water pH should be 5.5 - 6.5 after adding my fertilizers.

 

So, my plan is to reduce my Calcium Nitrate to compensate for the additional Nitrogen provided by the Nitric Acid. I understand how to do that, but what I need you guys to tell me is how do I bring the Calcium level back up to where it needs to be?

 

I slept through most chemistry classes at school and it's come back to bite me ;-)

[JungleBiker]

Most of the guys here that are putting nutrients into their irrigation water are not growing in soil, so I think what you're doing and what they're doing are not the same thing. They are growing hydroponically - you're not. They have to put every nutrient that the plant needs into their water. You already have a large reservoir of nutrients in your soil. Your're just trying to top up the nutrients that you think may be short. Nitrogen is usually one of them, and you may need one or two more, but shouldn't need to add all of them. 

 

I still suspect you may be adding acid unnecessarily. 

 

Myself and Rice555 have asked you about your soil pH and HereinThailand gave you a link with info about measuring soil pH. If you search this forum, many years ago Maizefarmer also gave instructions on how to easily measure soil pH.

 

I assume you already have a pH meter because you're telling us about your well water pH, so having a meter (assuming it is working normally and properly calibrated) means you're already half way there. Now you just need some distilled water (as used for topping up car batteries) and some scales to measure your soil sample and water to get the right ratio. Then you measure the pH of the soil water solution.  

 

I googled Samoeng and soil pH and it does appear as if soils in your area are naturally acid, though your soil may have been modified with lime, dolomite, ash or whatever. 

 

BTW, can I ask where did you get your Yara Calcium Nitrate and what was the price? Thanks. 

 

I just looked up the Yara product and here http://www.yara.com.au/crop-nutrition/products/yaraliva/0884-yaraliva-calcinit/ it mentions a pH of 6.0, i.e. acid! 

 

 

[DumbFalang]

I will do the 'quick and dirty' soil test but we have decided to take water and soil samples to Mae Jo University to get the job done properly.

 

The shop we buy most of our products from is across the road from Mae Jo Uni in Chiang Mai. It doesn't have an English name so check out the map on her Facebook page at th-th.facebook.com

 

The Yara Calcium Nitrate was around Bt500-590

[Scoop1]

Good morning all, dumbfarang, personally I think you are going about this the wrong way, what you should do to alleviate some of the confusion is formulate a balanced "Nutrient Concentrate" as is used in hydroponics, you don't have to have all the elements in the concentrate if you don't want, because you are growing in soil and hopefully it will supply what elements you don't add to the concentrate, also a properly balanced hydroponic nutrient when used with water that has a Ph. of 7.0 will drop it to around the Ph. 6.0 to 6.5 which is ideal, and a working strength nutrient solution at an EC of 1.6 fed to the plants will not toxify them in anyway.

Cheers

Scoop

[DumbFalang]

I do have a balanced Nutrient Concentrate but unfortunately it increases the pH rather than decreases it. On top of well water that is pH7.4 - I thought it would make sense to add some acid. After all the advice I've received on this thread I am now pretty happy with what we are doing - so Thanks to everyone who chipped in.

 

Scoop1 mentioned EC, which I noted while doing research but have not had the time to look into. Should I be considering buying an EC meter when growing in soil or is it something that is more for hydroponics?

[Scoop1]

Good morning all, dumbfarang, personally I think you are going about this the wrong way, what you should do to alleviate some of the confusion is formulate a balanced "Nutrient Concentrate" as is used in hydroponics, you don't have to have all the elements in the concentrate if you don't want, because you are growing in soil and hopefully it will supply what elements you don't add to the concentrate, also a properly balanced hydroponic nutrient when used with water that has a Ph. of 7.0 will drop it to around the Ph. 6.0 to 6.5 which is ideal, and a working strength nutrient solution at an EC of 1.6 fed to the plants will not toxify them in anyway.

Cheers

Scoop

[Scoop1]

Hi Dumbfarang, yes an EC meter is used in Hydroponics, it measures the electrical current in the nutrient, the more  fertilizer salts the stronger the nutrient and hence a higher Electrical Conductivity, I am glad you are happy with what you have worked out, the strawberries I grow in hydroponics are "Chandlers" a widely used American variety and are very nice,

Cheers

Scoop

[Scoop1]

19 minutes ago, DumbFalang said:

I do have a balanced Nutrient Concentrate but unfortunately it increases the pH rather than decreases it. On top of well water that is pH7.4 - I thought it would make sense to add some acid. After all the advice I've received on this thread I am now pretty happy with what we are doing - so Thanks to everyone who chipped in.

 

Scoop1 mentioned EC, which I noted while doing research but have not had the time to look into. Should I be considering buying an EC meter when growing in soil or is it something that is more for hydroponics?

Dumbfarang, can you tell me what fertilizer salts and what amounts you are dissolving in how many litres of water and I will put the calculator over it and see how balanced it is if you want!

Cheers

Scoop

[rice555]

Hello All, I was wondering why you are worrying about the fertilizer pH in the

overall picture, your soil should have the right pH and will adjust with just plain

water irrigation cycles as the plants use up the nutrients.

I was also wondering why the use of calcium for N verses ammonia based N

which is widely used soil fertilization?

Here's some of WESCO's water soluble fertilizers with TE's, you could just one

or two other single fertilizer's to get the NPK numbers you need/want. In hydro,

I mix each ingredient  from Kg's. down to .126g.

Anoer thing you may try next cycle is SDI, subsurface drip irrigation. Takes a little

getting use to, as you don't look for a wet surface. The water is applied to the root

zone, where it's needed. You don't want your drip to come in contact with plastic

film/mulch/row covering. You can use most drip tapes/line for SDI, but pressure

compensating is  the best. With PC tapes/lines you can soak with chorine or acid

at a lower pressure than it takes to open the emitter. Then rinse the system with

water out the clean out port.(all drip systems should  have one, usually at the lowest

place in  the system, it's all in the planning of the system, then the plants) 

rice555

[DumbFalang]

Thanks for all of that info - I'll need some time to digest it ;-)

[JungleBiker]

On 1/5/2017 at 8:49 AM, DumbFalang said:

It will be interesting to find out what you learn from Netafim.

 

 

Hi DF, 

 

1. There are different kinds of drip tape in terms of wall thickness and therefore durability. I think a lot of the stuff we find in the shops is the cheaper thin-walled stuff. I suggest you contact your local Netafim guy for more info about what product may best suit your needs: http://www.netafim.co.th/th/about/contact-us/  The better stuff can be used for several years. If rolled up every season, try to not to make kinks in the pipe because they will create unwanted holes/leaks.  

 

2. Apparently, (it would be better if you double check this info for yourself) some of their drip products can make use of regular (cheaper) fertilisers, so for the NPK you could use urea, DAP (18-46-0) and KCl (0-0-60).

 

Though for strawberries, which are more sensitive to salt than many crops, you may want to check whether the KCl is appropriate or not. Note that common 15-15-15 is often used as a basal fertiliser for many crops and the K comes from KCl.

 

As you probably know, urea is the cheapest form of Nitrogen, so why bother with expensive Yara calcium nitrate? Having said that, I've just read here that calcium nitrate can improve fruit colour and firmness: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0020/333362/Strawberry-fertiliser-guide.pdf 

 

3. When fertigating field crops grown in soil, it is common to use the above 3 fertilisers. You can use a simple venturi "injector", a single mixing tank, and apply one of the fertilisers per time, as needed. No need to do mixing or to apply fertiliser with every irrigation. 

 

4. Something I learned from another source some years ago, is that you can measure the nitrate and potassium levels in your strawberry plants by using these meters to measure the N and K in leaf petiole sap: 

http://www.specmeters.com/Nutrient_Management/Cardy_Plant_Nutrient_Meters.html 

The same source (a strawberry specialist in California) also shared the attached docs with me. 

Here http://www.haifa-group.com/knowledge_center/crop_guides/strawberry/mineral_nutrition_of_strawberries/ you can find information about testing nutrients in leaf petioles. 

 

JB

 

Fertization of Strawberries in Florida.pdf

Starter Fertilizer Need Questioned.pdf

[DumbFalang]

Thanks for sharing. I have the wife checking out Netafim but she can't find anything on the web site or Facebook page at 10cm spacing which is what we need for Strawberries. She'll probably end up giving them a call.

 

For Strawberries, we have no interest in the cheapest fertilizers - we just want the best. We charge a lot more for our berries than other growers so all decisions are driven by quality and not price.

 

I will check out the other links - Thanks again ;-)