salt deposits

[Spikylover]

Hello!
Does anyone know how to get rid of salt deposits from hard water in pots and on roots? Someone suggested using one cup of white vinegar for 20 liters of water. He said i can either soak the pots for 5 min in this acidic water or use it every time i water or at least for a couple of times tthen water with distelled water with a tablespoon of fertilizer added to it.
Is this good advice?

Thank you!

Rachel

[Steve Johnson]

Hello!
Does anyone know how to get rid of salt deposits from hard water in pots and on roots? Someone suggested using one cup of white vinegar for 20 liters of water. He said i can either soak the pots for 5 min in this acidic water or use it every time i water or at least for a couple of times tthen water with distelled water with a tablespoon of fertilizer added to it.
Is this good advice?

I've been acidifying my tap water with vinegar since 2012, and it works incredibly well. Unfortunately I'm not good with the math re. converting from US standard to metric measurements, but at least I can give you part of it. Per 1 US gallon of water, I'll add 1/2 teaspoon of Dyna Gro All-Pro 7-7-7 liquid fertilizer and 2-3 teaspoons of 5% white vinegar. 1 gallon = 3.8 liters, although to make it easier we can round it up a bit to 4, and if you're able to make the other necessary conversions yourself, you'll know what the amounts of fertilizer and vinegar should be. However, there are a few things to be aware of:

1. Although pH doesn't necessarily tell us about the level of alkalinity present in hard water, it's still useful to know what the pH of your water is. I use a pen-style digital pH meter, which is a great tool for testing your water before and after adding in the fert and vinegar. I tried using colorimetric indicator dyes and pH test strips, but my experience has shown that both tend to be highly inaccurate. Not that you can't use these methods yourself -- just be aware of the fact that you may be acidifying less than you could with a pH meter. You definitely don't want to over-acidify, so not enough is better than too much.

2. It's important to know the NPK values of your fert for 2 reasons. First, they should be pretty much in balance as you'll see with my 7-7-7. Too much of one tends to inhibit uptake of the others, especially problematic if the Nitrogen value is too low. Second, these numbers will tell you about how much fert you should be using. If you use the 7-7-7 diluted at 1/2 tsp. per gallon as a benchmark, you'll know if you have the right fert and whether or not you're diluting the proper amount. As with acidification, not enough is better than too much.

3. I grow the vast majority of my cacti in a soil-less pumice and granite gravel mix. This is essentially a hydroponic approach, so I have to fertilize every time I water. Mixes containing soil don't require fertilizing as often. Some people recommend fertilizing once a month, others suggest doing it with every 2nd or 3rd watering -- this really depends on the individual grower's experience.

4. Fertilizers lower the pH, so this should be taken into account for people who don't need to fertilize with each watering. If you go by the 1-gallon/4-liter rule and 2 or 3 teaspoons of vinegar are sufficient, then add 2 teaspoons when you're fertilizing, or 3 teaspoons when you aren't.

The point with acidification is to neutralize the bicarbonates (usually Calcium bicarbonate) present in hard water. However, fertilizers themselves can lead to salt buildup over time -- regardless of what may cause the buildup, I highly recommend that you flush your pots with rainwater/distilled water and no fert once a year during the growing season. If you see dirty brownish water draining out of the bottom of the pot, that'll be salts getting flushed out.

[Spikylover]

Hello!
Does anyone know how to get rid of salt deposits from hard water in pots and on roots? Someone suggested using one cup of white vinegar for 20 liters of water. He said i can either soak the pots for 5 min in this acidic water or use it every time i water or at least for a couple of times tthen water with distelled water with a tablespoon of fertilizer added to it.
Is this good advice?

I've been acidifying my tap water with vinegar since 2012, and it works incredibly well. Unfortunately I'm not good with the math re. converting from US standard to metric measurements, but at least I can give you part of it. Per 1 US gallon of water, I'll add 1/2 teaspoon of Dyna Gro All-Pro 7-7-7 liquid fertilizer and 2-3 teaspoons of 5% white vinegar. 1 gallon = 3.8 liters, although to make it easier we can round it up a bit to 4, and if you're able to make the other necessary conversions yourself, you'll know what the amounts of fertilizer and vinegar should be. However, there are a few things to be aware of:

1. Although pH doesn't necessarily tell us about the level of alkalinity present in hard water, it's still useful to know what the pH of your water is. I use a pen-style digital pH meter, which is a great tool for testing your water before and after adding in the fert and vinegar. I tried using colorimetric indicator dyes and pH test strips, but my experience has shown that both tend to be highly inaccurate. Not that you can't use these methods yourself -- just be aware of the fact that you may be acidifying less than you could with a pH meter. You definitely don't want to over-acidify, so not enough is better than too much.

2. It's important to know the NPK values of your fert for 2 reasons. First, they should be pretty much in balance as you'll see with my 7-7-7. Too much of one tends to inhibit uptake of the others, especially problematic if the Nitrogen value is too low. Second, these numbers will tell you about how much fert you should be using. If you use the 7-7-7 diluted at 1/2 tsp. per gallon as a benchmark, you'll know if you have the right fert and whether or not you're diluting the proper amount. As with acidification, not enough is better than too much.

3. I grow the vast majority of my cacti in a soil-less pumice and granite gravel mix. This is essentially a hydroponic approach, so I have to fertilize every time I water. Mixes containing soil don't require fertilizing as often. Some people recommend fertilizing once a month, others suggest doing it with every 2nd or 3rd watering -- this really depends on the individual grower's experience.

4. Fertilizers lower the pH, so this should be taken into account for people who don't need to fertilize with each watering. If you go by the 1-gallon/4-liter rule and 2 or 3 teaspoons of vinegar are sufficient, then add 2 teaspoons when you're fertilizing, or 3 teaspoons when you aren't.

The point with acidification is to neutralize the bicarbonates (usually Calcium bicarbonate) present in hard water. However, fertilizers themselves can lead to salt buildup over time -- regardless of what may cause the buildup, I highly recommend that you flush your pots with rainwater/distilled water and no fert once a year during the growing season. If you see dirty brownish water draining out of the bottom of the pot, that'll be salts getting flushed out.

Thanks for the detailed reply steve!!
I am a chemical engineering student so the math wouldn't be a problem.
I still haven't got the heart to go fully hydroponic but im at 10-15% organic matter and reducing.
First thing im gonna do is flush with acidified distilled water and then go back to my watering habits but with acidification.
Almost all our rock formations are limestone so you get why we have such a hard water.
Again, many thanks!

[Steve Johnson]

Flushing with distilled water is a great idea, although since it's pH-neutral (7.0), I'm not sure if you'll need to acidify for the flush. Regular watering with hard water is another matter, so your watering solution should have a pH range of 5.0-6.0 after you've added the vinegar (and fert whenever you're fertilizing). Since you're a chemical engineering student, you may have access to a chem lab with a pH meter that'll be better than my pen-style meter. If that's the case, you'll be able to accurately test the pH of the acidified water. I shoot for the lower end of that range (5.0-5.5), so a good meter will be helpful in determining the amount of vinegar that'll give you the proper level of acidification.

Glad I could help -- even if you don't see much of a response to your new watering regimen over what's left of this year's growing season, I think you'll be pleasantly surprised by the improvement you'll see in your plants next year.

[DaveW]

The problem can be with plants in the house where splashing water around is not an option. In that case do not allow plants on saucers to stand in the drained water and reabsorb it, but empty the saucer of water immediately it accumulates. Acidifying the water of course helps to prevent the build up of salts from alkaline tap water, but may not cure build up of salts through over fertilisation and selective absorption by the plants, leaving chemicals they cannot use in such quantities in the soil. You need only enough fertiliser for optimum growth of the plant, since over fertilisation can cause salts build up and actually inhibit growth.

In the greenhouse or outdoors the problem is not so great, you water every time so the water runs freely out of the drainage hole of the pots and never catch and reuse it or you are simply adding the unwanted dissolved salts back. Over fertilisation can cause problems too since our plants do not grow at the same rate as most plants and therefore do not use fertiliser at that rate either. Using fertiliser at half the strength recommended on the packet for "normal" plants is usually recommended, that is unless it is a special cactus fertiliser where the recommendations will have been adjusted for our plants anyway.

As Steve says, leaching the pots occasionally also gets rid of salts build up, as does regular repotting. However if you use mineral based soil you may not want to throw them away but leach and reuse them. There is nothing in that case stopping you repotting them in fresh mineral soil then putting the old out in a container with drainage holes in the bottom in the open air and letting the rain leach it for a month or so before reusing it.

https://www.youtube.com/watch?v=0FGXrkkcKHk

http://www.healthyhouseplants.com/index ... -that.html

If you freely water plants so water flows out the pots drainage hole every watering and is not reabsorbed the salts do not build up to the same extent anyway. Many people underwater plants, giving only a few drops of water each time they water so they don't get the flushing action of water running freely out of the pots drainage hole and in that situation salts build up. I even knew one person growing them on a windowsill who used to give each pot a set number of teaspoons full of water each time. The old recommendation of water well so it flows out of the drainage hole, then leave them to dry out before watering again is still the best advice.

Growing in purely mineral soils is more akin to hydroponics. This one has a bit of a frantic American commentary, but you should be used to it over there.

https://www.youtube.com/watch?v=k9pxmhCuVCM