Drosophylla tolerance of hard water

[Tanukimo]

Drosophyllum tolerance of hard water

Has any had any experience using hard water for Drosophyllum? I don't have one now but when I was mixing the substrate of peat, sand, perlite, and vermiculite for mine a few years ago, there was so much to mix that my RO system wouldn't be able to supply it so I used hose water and planted the plant in that. The water in southern California (at least the area I live in) is very hard and I'm pretty sure most carnivores would not be able to take it for very long but the Drosophyllum didn't seem to have any reaction to it. Granted I did top-water it with RO water but definitely not enough to flush out all the minerals since it was a 3 feet tall pot. The plant survived about a year and flowered but I lost it after that. I am tempted to get another one and try watering it with hose water to see if it will survive.

 

[bluemax]

An interesting question. It does seem that Drosophyllum grows naturally in soil that should have a pretty high mineral content.

 

[nimbulan]

I've found it difficult to find any information about TDS tolerance of any but the most common plants. I've looked for information about Roridula many times without success.

 

[DJ57]

What is the TDS of your hose water (how hard is it)? Also, do you know the TDS of your soil contents? Some peat brands, if you use that in your mix, has high TDS levels all by itself. Do you know why you lost your Droso after only a year?

My city water has fairly low TDS levels and that is what I use to water my Drosophyllum, so I have no idea how tolerant they are to hard water. I suspect though that Drosophyllum may be more tolerant of higher TDS levels than most other CPs but for long-term health, given there is little to no written information on this subject that I can find either, I would not recommend using water with a TDS much higher than 100 ppm unless you flush the soil good with distilled, rain, or RO water several times a year to be on the safe side.

You could do an experiment with a couple of your future Droso plants in smaller pots, like 8 or 10” terra cotta pots, and use your hose hard water for one and distilled, rain, or RO water on the other and be the first, it seems, to write about your results? I think this would be a very worthwhile experiment and informative for others with the same question

 

[Tanukimo]

According to this link, my TDS is 315, although I haven't measured it. I believe I lost it being kept too wet after flowering, although I wasn't there personally so I'm not sure. I'm pretty sure the peat is okay because I grow some of my plants in pure peat of the same brand and I haven't seen any problems yet. I might have some seeds still in the pot (didn't bother collecting them from the flower) so I might try that experiment in the future.

 

[Fygee]

Soil in dry, arid areas is naturally high in minerals and salts. I would presume that they wouldn't be affected by hard water.

 

[fredg]

Just noticed this thread.

I understand that the Drosophyllum pot was watered with tap water at the beginning and then RO water was used thereafter.

If this is the case it is no surprise to me that the plant showed no ill effects. I have used tap water on many occasions when I've run out of rainwater and my plants showed no ill effects either. By plants I mean all the genera I have, not just Drosophyllum.
My tap water has a TDS circa 310 but I was watering with tap water occasionally long before TDS meters became available. In fact TDS was never mentioned in those days, it was specified that the water had to be acid, a pH below 7. I recall using Sulphuric acid (H₂SO₄) in aged water way back yonder to reduce the pH.
A couple of waterings with straight aged tap water would have been the norm in most summers. At other times I may have used half tap, half rainwater to eek out the supplies. Media was not rinsed through afterwards, I just continued to tray/lagoon water as usual.

Our current summer has been extremely dry so I ran out of rainwater again despite my 1300 litre stock. I purchased a small RO filter just to keep me going and used it for approximately 10 days which brought me back to a decent water stock. The TDS reading was circa 7 and I did notice that the algae bloom in the lagoons disappeared after a couple of waterings. Nothing in there to even get a little green water. No wonder people using RO water indoors have to fertilise, the poor plants are starving. Not even the odd decomposed and liquified slug to keep them going