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TDS and PPM for Nepenthes?

Tower

Jake
Hi Guys,
I ran into a very debatable subject with the TDS with water. Does anyone have a idea of what would be tolerable? According to a well known online vendor anything under 160 PPM is optimal.
 
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I heard under 50PPM is the way to go but I think that is very conservative. I recently read on another forum that someone had been watering with tap water for quite a while.

I personally just don't see how Nepenthes "can't seem to tolerate any nutrients at all around their roots" while plants that grow in the same cliffs around them with roots just as delicate are okay with tap water. For example, Paphiopedilums grow in lowland and highland areas where Nepenthes are found. They can a hefty amount of fertilizer with delicate, fuzzy roots. The low nutrient thing probably has some truth behind it, but I feel like at one point somebody said "There can't be any nutrients in their water or their roots will burn!" and everyone jumped on the bandwagon.

Have you ever seen photographic evidence of a Nepenthes killed from minerals? I personally haven't. Not to say it can't happen, but I've never heard of that scenario.

Not completely dissing the idea, I'm sure there is reason behind it. My point is that I think they can take considerably more minerals than people say. Every species is different, though.
 
Hello Pineapple,
Yea I completely agree, Ive heard the rumors that neps can take more tds then they are credited for. So, I was curious what the general census was on neps. Personally, Im not sure if I would be willing to mass murder the plants I have because I took a chance at watering them with 150 PPM. Although, I could always experiment on one plant :)
 
Under 50. 160 would kill your plant stone dead. You could possibly get away with it temporarily by washing the pot out frequently, but why risk it? RO filters are cheap nowadays.
 
Hi Guys,
I ran into a very debatable subject with the TDS with water. Does anyone have a idea of what would be tolerable? According to a well known online vendor anything under 160 PPM is optimal.

Tolerable for which genera??! Its important to make the distinction between the "clean water requirements" for Drosera VS Nepenthes VS Sarracenia. Water that is far too mineral-rich for Drosera might be easily tolerated by Nepenthes. However, I don't really believe that water with a TDS reading of 160 PPM would be very good for any genus, as a long-term solution. That concentration of salts would send most any Drosera into rapid decline.

Yes, some people water their Nepenthes with tap water. It IS possible to have very usable tap water from a municipal supply, but you need to TEST IT to know how usable it is! Without that knowledge, you could be making tragically bad assumptions. Our local municipal water supply annually tests at under 50PPM TDS, and so it is perfectly good for any CPs (assuming you do occasionally flush the pots; at even 50PPM, salts can accumulate if its a closed system). However, I am on a well out in the outskirts and I have to either collect rainwater (did that for one year, got tired of the labor involved) or find another source, so I installed a RO unit. Problem solved.

And yes, Nepenthes aren't like most other CP genera - they grow in environments that - while often nutrient deprived - are far from devoid of nutrients. Birds and animals contribute what must be significant amounts of nutrient to the ecosystem/root zone, and some species live in mineral soils that sometimes contain high concentrations of Nickel and other toxic metals. "Tolerance", when describing the ability of each genus (Not to mention individual species) to make use of a water supply that contains dissolved minerals, is a much more finely grained problem than you might think on casual inspection. Whatever you do, don't rely on hearsay and anecdotal information - it will just as often mislead you as inform you. Go to trusted sources for information, IE: people who have written books on the subject. (and growers who have many years of experience)
 
Every Nep species is different. This is the root of the problem here, there are some species that will require very clean water but somehow it just got accepted as a general rule that all Neps (well CPs in general) need very clean water. With the rarer plants please play it safe, but with the common ones some documented experimentation would be a great next step.

I would be interested to know what the TDS of the coffee bath or fert solutions some people are feeding their Neps is just for random useless knowledge.

TDS is another one of those things people just don't really understand or think about enough.

From Wikipedia "Total Dissolved Solids (often abbreviated TDS) is a measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized or micro-granular (colloidal sol) suspended form."

One persons 150 TDS water may be perfectly safe while another persons 150 TDS water could kill your plants. What those combined substances are is very important and without getting your cities water reports TDS really just lets you know what ballpark your in.

With all that said my tap water is 160-170 and I'll never use it to water any plants I don't want to lose.
 
Every Nep species is different. This is the root of the problem here, there are some species that will require very clean water but somehow it just got accepted as a general rule that all Neps (well CPs in general) need very clean water. With the rarer plants please play it safe, but with the common ones some documented experimentation would be a great next step.

I would be interested to know what the TDS of the coffee bath or fert solutions some people are feeding their Neps is just for random useless knowledge.

TDS is another one of those things people just don't really understand or think about enough.

From Wikipedia "Total Dissolved Solids (often abbreviated TDS) is a measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized or micro-granular (colloidal sol) suspended form."

One persons 150 TDS water may be perfectly safe while another persons 150 TDS water could kill your plants. What those combined substances are is very important and without getting your cities water reports TDS really just lets you know what ballpark your in.

Yes, absolutely.
 
I got the great idea to double filter the water, with doing that, I can now get it down to 20 ppm! Whoo hoo! Thanks everyone for the help
 
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The way I see the TDS thing...

Some water is just too hard. done. if it dries and leaves a residue, its probably not great.
BUT
these plants are way tougher than we give them credit for. added to that, the way most people grow/water their drosera, VFT and sarras are the reason behind their sensitivity IMO.
okay, here goes:
when you leave your plant in a tray of water, the water in the soil evaporates off the surface (and leaves any solute behind) - then draws more water (containing solutes/salts) up. replay this scenario over and over for months/years and even the purest of pure waters (no water can be 100% pure even if you purchase the highest grade UHPLC grade water for mass spectrometry) will eventually deposit enough salt in the soil to kill your plant.

now, I never subscribed to the RO water buzz and always had those plants standing in a tray of water and would top it up when needed, then I would flush the soil when I noticed salt stress. then I started just top watering all of them and I have never looked back. all my drosera, VFT and sarras get watered when my veggies get watered and they grow perfectly well.

So, in closing. these plants are far more sensitive to our growing methods than the water we use. it just makes sense. even 1ppm water WILL eventually cause a problem if the pots are never flushed and soil never replaced.
Growing any plant in a way which allows salt to build up like that will kill it. some merely faster than others.
We generally top water Neps so never see this problem because there is no reason for salts to build up between waterings.
 
  • #10
With 80% of the locals living in highrise apartments, we use mostly tap water for our Neps. The TDS for the water in my area is about 110ppm and it is fine for them. It takes about 3-4 months for the minerals to show up on the top most layer of the sphagnum moss used as media. I wouldn't think 100ppm will kill the Neps but it certainly contributes to the media rotting faster...leading to root rot for the Neps.
 
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  • #11
after posting above, I went to check my local water and its 130+ppm tds and my Neps have never gotten anything else.
 
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