I installed a venturi system in my irrigation hose and I am lowkey thrilled (excuse the gen Z language). My water is not too hard, doesn't leave white marks on leaves for instance, but its pH is 8! I add citric acid through venturi and the water has now a pH of 6.5! I hope this will make a difference for my plants. For a small garden like mine, the cost is negligible, less than 1 dollar per watering for citric acid. Anyone else has tried this?

Here is a photo of the Venturi; I know it looks totally amateur-ish but oh well, it works. I dilute the citric acid in the black deposit; I am planning to get a bigger one so I don't have to refill every time.

 

Here you go @Than one of five Venturis we have at work! 

We have 3 1000 litre shuttles for fertilisers that last two days in between refilling. And use fertiliser by the tonne! It’s a fun job it’s not rocket science but the hot days keep you pretty busy. It’s called irrigation but in fact we call it irritation, great when it’s working but when it’s not working and something is wrong on a 38 degree celcius day in poly tunnels, let’s just say the pressure is on and we are not talking about water pressure! 

Try Agri buffa to lower ph. 

28 minutes ago, happypalms said:

Try Agri buffa to lower ph. 

An Australian product I see. I bet it will be more expensive than humble citric acid

9 hours ago, Than said:

An Australian product I see. I bet it will be more expensive than humble citric acid

Anything in Australia is expensive at the moment, and I think the freight to your door would be even more expensive! 

7 hours ago, happypalms said:

Anything in Australia is expensive at the moment, and I think the freight to your door would be even more expensive! 

You can find it in Greek shops too but still I bet citric acid will work out much cheaper.

1 hour ago, Than said:

You can find it in Greek shops too but still I bet citric acid will work out much cheaper.

You could try elemental Sulfur, cost is a big factor on a large scale or if used continuously.  And if it’s for the home garden I would not look at the cost but what would be effective. Be careful not too lock up your soil making matters even worse. 

3 minutes ago, happypalms said:

You could try elemental Sulfur, cost is a big factor on a large scale or if used continuously.  And if it’s for the home garden I would not look at the cost but what would be effective. Be careful not too lock up your soil making matters even worse. 

You are right; My garden is only 400 sq.m. so the cost is not an issue. I apply sulfur twice a year. The soil's original pH is 8,2, which is quite high, so I believe I have to combine all those methods to see results: sulfur + citric acid in water + amendment with acidic soil + humic acids.

I'll do another soil test in the future to see if I have achieved anything. What's your pH?

51 minutes ago, Than said:

You are right; My garden is only 400 sq.m. so the cost is not an issue. I apply sulfur twice a year. The soil's original pH is 8,2, which is quite high, so I believe I have to combine all those methods to see results: sulfur + citric acid in water + amendment with acidic soil + humic acids.

I'll do another soil test in the future to see if I have achieved anything. What's your pH?

8.2 that’s a mega high ph. My ph is around 6 to 5.5, most nutrients are available. I do get a slight  phosphorus deficiency due to the sandy soil leaching, and that’s most of the Australian soils around. All I do for fertiliser for the garden is chicken poo pellets. Broad casting handfuls around and the odd handful on the hungry looking palms. I used to broadcast a synthetic NPK mixture, but found that it was not good for the chamaedoreas, prolifiic blue was the one I used. There are not many specific palm fertilisers available in bulk in my area it’s more fruit tree fertilisers. And with so many different palms from all around the globe in my garden it’s not easy to use a NPK mix. So just the good old chicken poo pellets for me! 

5 hours ago, happypalms said:

8.2 that’s a mega high ph. My ph is around 6 to 5.5, most nutrients are available. I do get a slight  phosphorus deficiency due to the sandy soil leaching, and that’s most of the Australian soils around. All I do for fertiliser for the garden is chicken poo pellets. Broad casting handfuls around and the odd handful on the hungry looking palms. I used to broadcast a synthetic NPK mixture, but found that it was not good for the chamaedoreas, prolifiic blue was the one I used. There are not many specific palm fertilisers available in bulk in my area it’s more fruit tree fertilisers. And with so many different palms from all around the globe in my garden it’s not easy to use a NPK mix. So just the good old chicken poo pellets for me! 

Wow you live in heavens. Acidic soil, no frosts, sandy soil... and your only problem is that you have to use natural fertilizer! Life isn't fair 

2 hours ago, Than said:

Wow you live in heavens. Acidic soil, no frosts, sandy soil... and your only problem is that you have to use natural fertilizer! Life isn't fair 

Hopefully you do not have an evil eye🙃

On 5/18/2026 at 7:49 AM, Than said:

An Australian product I see. I bet it will be more expensive than humble citric acid

Agri Buffa is designed for crops that will be harvested, not long term use.

AI Overview

 

 

 

Agri-Buffa is a highly acidic spray adjuvant used to acidify, buffer, and act as a surfactant for agricultural tank mixes. Long-term use requires careful soil management and equipment maintenance to prevent adverse effects like soil acidification, metal corrosion, and chemical damage. [1, 2, 3, 4, 5]

Key considerations for long-term use include:

• Soil & Water Impacts: Repeated acidification over time can lower soil pH, which may eventually require liming. However, Agri-Buffa is biodegradable, and organic accumulation in the soil is generally low compared to the active pesticidal chemistries it is mixed with.
• Corrosion Risks: The product is highly corrosive (pH < 1.0). Long-term use requires strict equipment maintenance. Failure to rinse sprayers and boom lines can degrade metal and plastic components over time.
• Microbial Health: While Agri-Buffa itself is an adjuvant, the long-term use of the pesticides and herbicides it carries can significantly alter soil microbiomes.
• Best Practices: Always conduct regular annual soil tests and pH monitoring to ensure your soil's chemistry remains within the ideal agronomic range. [1, 2, 3, 4, 5]

If you look further they warn that long term use or overuse can remove the waxy cuticle layer as agribuffer is a surfactant and penetrant.  Probably quite effective for crops that will be harvested this growing season.  But I would be careful with palms, you really dont want to remove the cuticle wax as its protective against sunburn and pathogen entry.

20 hours ago, Than said:

Wow you live in heavens. Acidic soil, no frosts, sandy soil... and your only problem is that you have to use natural fertilizer! Life isn't fair 

There’s a lot I can’t grow and there’s a lot I have killed trying, iam quite happy to black sandy soil, and a lot of sandstone rocks in my soil. Plus the ocean influence, my elevation is around 130 meters. So quite a unique microclimate, a palm growers paradise close to halfway in between Sydney and Brisbane. 

12 minutes ago, happypalms said:

There’s a lot I can’t grow

Can you name some species that you thought you could grow but they didn't make it there?

On 5/20/2026 at 6:52 PM, Than said:

Can you name some species that you thought you could grow but they didn't make it there?

Pelagodoxa henryana, brassiophoenix schumanii, Calpytrocalyx benga dawn, Areca catechu, drymophloeus oliviformis, cocos nucifera. All these ones I thought they had a chance and keep on trying. Then you realise it’s no use in on trying so you learn after a while, not to waste your time on trying, you know the signs of cold damage and necrosis on a palm. Yet we tell ourselves it wasn’t the cold and try again, it died due to some reason we tell ourselves. But this is how we learn to grow from making mistakes. It makes for a better grower and the quality of your plants increases!

I live in the low desert of Arizona with our tap water coming in at 7.8 pH almost year round. Winter is 7.5. I've used sodium bisulfate to buffer my water for about 4 years. The results have been consistently excellent with far less fertilizer required.

I grow a big cycad collection in containers, and some succulents in ground. I buffer down to 6.2 to 6.4.

I found that using citric acid to buffer seems to drift a lot and lose it's effect at about day 3 after watering. But the sodium bisulfate holds steady at the desired pH.

I buy this buffer at a retail pool supply store quite inexpensively. It's a dry acid that claims to condition the water to keep the dissolved calcium carbonate in suspension to rinse out at each watering. I did notice that old calcium deposits on my older plants' containers has largely dissolved and washed away at this point.

I learned about this from an elderly cactus grower here in the southwest.

8 hours ago, GeneAZ said:

I live in the low desert of Arizona with our tap water coming in at 7.8 pH almost year round. Winter is 7.5. I've used sodium bisulfate to buffer my water for about 4 years. The results have been consistently excellent with far less fertilizer required.

I grow a big cycad collection in containers, and some succulents in ground. I buffer down to 6.2 to 6.4.

I found that using citric acid to buffer seems to drift a lot and lose it's effect at about day 3 after watering. But the sodium bisulfate holds steady at the desired pH.

I buy this buffer at a retail pool supply store quite inexpensively. It's a dry acid that claims to condition the water to keep the dissolved calcium carbonate in suspension to rinse out at each watering. I did notice that old calcium deposits on my older plants' containers has largely dissolved and washed away at this point.

I learned about this from an elderly cactus grower here in the southwest.

Thank you for your input; this is very interesting!

Do you do this in combination with other methods, i.e. sulfur pellets on the ground, humic acids...?

Also, do you use the sodium bisulfate in every watering?

On 5/27/2026 at 5:19 AM, GeneAZ said:

I live in the low desert of Arizona with our tap water coming in at 7.8 pH almost year round. Winter is 7.5. I've used sodium bisulfate to buffer my water for about 4 years. The results have been consistently excellent with far less fertilizer required.

I grow a big cycad collection in containers, and some succulents in ground. I buffer down to 6.2 to 6.4.

I found that using citric acid to buffer seems to drift a lot and lose it's effect at about day 3 after watering. But the sodium bisulfate holds steady at the desired pH.

I buy this buffer at a retail pool supply store quite inexpensively. It's a dry acid that claims to condition the water to keep the dissolved calcium carbonate in suspension to rinse out at each watering. I did notice that old calcium deposits on my older plants' containers has largely dissolved and washed away at this point.

I learned about this from an elderly cactus grower here in the southwest.

18 hours ago, Than said:

Thank you for your input; this is very interesting!

Do you do this in combination with other methods, i.e. sulfur pellets on the ground, humic acids...?

Also, do you use the sodium bisulfate in every watering?

What is the mixing rate for sodium bisulfate? It is more than impressive, than a slow dying Macadamia in my garden has produced the first decent leaves after three years of total refraining from fertilizers and one year of moderately decent rainfall, which reduced use of utility water.

1 minute ago, Phoenikakias said:

What is the mixing rate for sodium bisulfate? It is more than impressive, than a slow dying Macadamia in my garden has produced the first decent leaves after three years of total refraining from fertilizers and one year of moderately decent rainfall, which reduced use of utility water.

6 minutes ago, Phoenikakias said:

Wow, that is great to know! Did you also try citric acid? I read that using sodium bisulfate long-term can ruin the soil by making it unable to hold water.. it's just smth I read, I don't know if it's true.

No, nothing whatsoever for water correction. What is the dose you apply?

3 minutes ago, Phoenikakias said:

No, nothing whatsoever for water correction. What is the dose you apply?

20-25 grams of citric acid in 10 litres of water. That lasts about 30min in my garden but of course every garden is different and depends on the number of plants you are watering.

11 minutes ago, Than said:

Wow, that is great to know! Did you also try citric acid? I read that using sodium bisulfate long-term can ruin the soil by making it unable to hold water.. it's just smth I read, I don't know if it's true.

Citric acid apparently is friendlier to the soil but the problem it has is that with time bacterial slime builds in the hoses.

What do mean by 'last'? I am completely ignorant. I am so occupied with 5h3 protection of the plants from the rpw and paysandisia, both in terms of time and money, that I did not wish to plunge also in to water correction. But for couple plants I think I can make an exception through hand watering.

4 minutes ago, Phoenikakias said:

What do mean by 'last'? I am completely ignorant. I am so occupied with 5h3 protection of the plants from the rpw and paysandisia, both in terms of time and money, that I did not wish to plunge also in to water correction. But for couple plants I think I can make an exception through hand watering.

So I dilute 25 grams of citric acid in 10 lt of water and I connect it to the venturi system which then inserts it into the main watering hose. It's easy. I am planning to buy a 30 lt water container so it lasts for 2 waterings. And remember, you don't have to use it on every watering; this can actually be harmful. So with that mixture of 30 lt I can do two waterings. In the summer I will use venturi twice a week so the 30lt will be enough for a week.

11 minutes ago, Than said:

So I dilute 25 grams of citric acid in 10 lt of water and I connect it to the venturi system which then inserts it into the main watering hose. It's easy. I am planning to buy a 30 lt water container so it lasts for 2 waterings. And remember, you don't have to use it on every watering; this can actually be harmful. So with that mixture of 30 lt I can do two waterings. In the summer I will use venturi twice a week so the 30lt will be enough for a week.

Do you water the plants directly from the 10 lt solution or do you dilute further prior to use?

3 minutes ago, Phoenikakias said:

Do you water the plants directly from the 10 lt solution or do you dilute further prior to use?

As I said Venturi inserts the solution into the main hose so it gets diluted there. The first time you use the system, you need to do a pH test of the water that comes out from the drippers, and adjust the Venturi valves until the water has the pH you want. I use a simple pH test kit sold at pet shops for aquariums.

Dealing with 5h3 sounds stressful... I hate those pests.

10 hours ago, Than said:

Wow, that is great to know! Did you also try citric acid? I read that using sodium bisulfate long-term can ruin the soil by making it unable to hold water.. it's just smth I read, I don't know if it's true.

Sulfites will likely accumulate in the soil as sulfates after oxidation, and sulfates don't biodegrade easily. Sulfates are not nasty toxicity wise, but they can be accumulated in the soil to excess over time(years) and they will tend to draw water from the roots by osmotic pressure at some accumulated concentration. At a high level there are sulfur toxicity issues which stunt growth.

Citrates are far more friendly to long term soil composition

Biological Decomposition (Metabolism)

In living organisms, citrate is broken down during cellular respiration in the Citric Acid Cycle (also known as the Krebs cycle). [1, 2, 3, 4]

• Mechanism: The six-carbon citrate molecule undergoes progressive enzymatic catabolism, losing carbon atoms as \(CO_{2}\).

• Result: Through a series of oxidations and cleavages, citrate is ultimately broken down into a four-carbon acid called oxaloacetate, which then restarts the cycle. [1]

Citrate is also highly biodegradable in the environment. Because it is a natural organic compound, it breaks down harmlessly under both aerobic and anaerobic conditions in conventional wastewater treatments. [1]

I would use the citrate for long term soil health.

On 5/27/2026 at 4:03 AM, Than said:

Thank you for your input; this is very interesting!

Do you do this in combination with other methods, i.e. sulfur pellets on the ground, humic acids...?

Also, do you use the sodium bisulfate in every watering?

I buffer every watering to 6.4 to 6.2. I don't use any other buffering or conditioning agents. I use a liquid feed once monthly in temperatures over 100F. No pellets or humic acid.

13 hours ago, Phoenikakias said:

What is the mixing rate for sodium bisulfate? It is more than impressive, than a slow dying Macadamia in my garden has produced the first decent leaves after three years of total refraining from fertilizers and one year of moderately decent rainfall, which reduced use of utility water.

Well, the rate of buffer is dependent on the pH of your water. If you have a tank or buckets, you would fill them up with your water as it comes to you; then use a pH meter to see your starting pH of untreated water; then add the bisulfate, which is granular like sugar, in small amounts and stir it to dissolve. If you use a proportioner, you make a solution of bisulfate dissolved in water and that's the concentrated buffer that your proportioner sucks up and uses.

I have a 42 gallon vat that I use, which requires 1 1/2 teaspoons of the bisulfate powder to bring the pH down from 7.5 to 6.2. My sister has a few patio plants, and she waters with a 3 gallon watering bucket which requires 3 pinches of bisulfate where the amount used is just the quantity she can hold in a pinch of her index finger and thumb.

By the way, if you mix this up, you can store the buffered water and the pH is stable in solution and never drifts up or down.

Water pH here is identical to yours both during winter and summer!

using any kind of buffer, sulfite or citrate, allows you to control the pH of the water you irrigate with but after you add it to the soil the acid may just react with alkaline elements in the soil and go alkaline again especially if that soil is calcareous. High calcium will override the buffer capacity easily in molar equivalents if the soil interacts with the water. But if your soil is neutral and the water is alkaline this works. THink of it this way, in order for th epH to be alkaline there has to be a small molar equivalent of base (dissolved calcium hydroxide for example), a very low concentration. If you have a lot of calcium in the soil it will dissolve and drag the pH of the water once its in the soil to alkaline. Is your soil calcareous or high in calcium? I would typically test the soil not the irrigation water to see what pH the plant roots will be exposed to. Soil testing is more complicated in terms of interferences to tests. I'd take a number of samples in the area and have them tested to see what the soil pH is.

7 hours ago, sonoranfans said:

using any kind of buffer, sulfite or citrate, allows you to control the pH of the water you irrigate with but after you add it to the soil the acid may just react with alkaline elements in the soil and go alkaline again especially if that soil is calcareous. High calcium will override the buffer capacity easily in molar equivalents if the soil interacts with the water. But if your soil is neutral and the water is alkaline this works. THink of it this way, in order for th epH to be alkaline there has to be a small molar equivalent of base (dissolved calcium hydroxide for example), a very low concentration. If you have a lot of calcium in the soil it will dissolve and drag the pH of the water once its in the soil to alkaline. Is your soil calcareous or high in calcium? I would typically test the soil not the irrigation water to see what pH the plant roots will be exposed to. Soil testing is more complicated in terms of interferences to tests. I'd take a number of samples in the area and have them tested to see what the soil pH is.

My soil's original pH was 8,2! With lots of calcium. I have added very acidic topsoil (pH 3.8) but I haven't measured since. I apply sulfur pellets twice a year. Do you think lowering the water's pH lowers the pH in the soil around roots even temporarily so that plants can absorb nutrients? I guess even if the pH is only lowered for few hours that's still a gain, right?

In that respect I believe sodium bisulfate beats citric acid as it is more stable in the ground?

8 hours ago, Than said:

My soil's original pH was 8,2! With lots of calcium. I have added very acidic topsoil (pH 3.8) but I haven't measured since. I apply sulfur pellets twice a year. Do you think lowering the water's pH lowers the pH in the soil around roots even temporarily so that plants can absorb nutrients? I guess even if the pH is only lowered for few hours that's still a gain, right?

In that respect I believe sodium bisulfate beats citric acid as it is more stable in the ground?

Sounds like you are doing everything you can given soil pH of 8.2. After adding the sulfur for a few years it may work. But calcium is not evenly distributed in soils, there can be layers of enriched soil you are not sampling. Chelation of nutrients regularly using humic acid will do more to make nutrients available than adding citric acid. You might experiment with iron deficiency susceptible plants to see how things are working out with your citric and sulfur treatments. They would be line "canaries in the coalmine", probably cheaper than lots of soil pH tests. they used to keep canaries in the coal mines to detect toxic gases before miners were killed. This was before measurement instruments were available. I might use humic acid drenches once a month or so depending on soil drainage. Once a month for clayish soil, more frequently for higher drainage loam or sandy soil.

1 hour ago, sonoranfans said:

Sounds like you are doing everything you can given soil pH of 8.2. After adding the sulfur for a few years it may work. But calcium is not evenly distributed in soils, there can be layers of enriched soil you are not sampling. Chelation of nutrients regularly using humic acid will do more to make nutrients available than adding citric acid. You might experiment with iron deficiency susceptible plants to see how things are working out with your citric and sulfur treatments. They would be line "canaries in the coalmine", probably cheaper than lots of soil pH tests. they used to keep canaries in the coal mines to detect toxic gases before miners were killed. This was before measurement instruments were available. I might use humic acid drenches once a month or so depending on soil drainage. Once a month for clayish soil, more frequently for higher drainage loam or sandy soil.

Thank you Tom. I do that too actually, I water with humic and fulvic acids monthly. I also provide Fe EDDHA monthly to those plants that show Fe deficiency symptoms, such as gardenia and hibiscus. To Syagrus too although I have no clue what deficiency, if any, it has..

So basically I apply 4 different methods: sulfur pellets + humic acids + citric acid in the water + chelated iron.. the struggle is real.

Come to think about it, gardenia would make a nice canary in the coalmine. She is a drama queen so she will for sure let me know she doesn't get enough Fe, she is cheap and easily replaceable..