Water adjustments...

[Smel]

Hi,
While visiting Ralph Martins web site I came across a link to an article on Water and how our plants like it! It seems that an acidic water is best, it describes how a newly potted plant grow well for the first year or so, but then slows down, and by year 3 is very slow. My local water is very hard and I try to use rainwater as much as I can, but I do get limescale in some pots. Using some simple kit I just tested my water-butt water a TDS (Total Dissolved Solids) meter gave a very low reading of 006 and universal test paper a PH of about 6.5.

but this article speaks of adding things like white vinegar or Citric acid to bring the PH down to 5.5. both authors claim a good improvement in growth and health of their plants.
Does anyone use anything like this? or what do you do to your water that's a bit different....

here's the link, Really worth a read! sure Ralph wouldn't mind: https://www.rrm.me.uk/Cacti/Cactus%20an ... linity.pdf

Mel.

[MatDz]

it describes how a newly potted plant grow well for the first year or so, but then slows down, and by year 3 is very slow.

Playing devil's advocate, does this mean, that a regular repotting into a slightly acidic substrate (where appropriate) would be enough to keep plants happy?

Also, be careful with Ralph's website, it quickly becomes addictive!

[Smel]

Hi Mat,
Yes you could be right, but would you want to repot everything every year or so! Cacti don't seem to like having their roots disturbed. I think I'm going to give it a try.

[habanerocat]

Ericaceous fertiliser can help keep the ph down ongoing.
I use it on South American cacti. Normal No. 8 on North American.

[iann]

You're not going to get any problems using that rainwater, but if you pour on hard tapwater then that will fairly quickly lead to trouble with plants that don't tolerate alkaline conditions. Most, although not all, cacti from Mexico northwards are fine with alkaline soils to the point where adding limestone to the soil may actually help some of them. South of that, many species won't tolerate any lime, although there are some that hail from limestone soils, a few of the Caribbean species, and some of the Brazilians. Limestone buildup from hard water may cause other issues such as impeding drainage, and non-alkaline water will help to release some nutrients, so even if you've added limestone chips to a pot, you probably still want to use rainwater if at all possible. Adding acids to hard water is a poor substitute for rainwater as there will still be a lot of salts in the water, just ones that are less immediately alkaline.

[ralphrmartin]

In Cardiff, the water coming out of our tap was about pH 8, so I added a teaspoon of vinegar per bucket of water to make it nearer pH 5.5. I originally got the idea from Buxbaum's book "Cactus Culture based on Biology" where there's a photo showing seedlings grown at different pH.

Now I live in North Wales, the rock round here is mainly pretty acidic, and the tap water is about pH5.5 anyway, so I dont add any vinegar any more. I use Ericaceous fertiliser / compost for e.g. my South American cacti. Iann is spot on with his comment about rock types in different parts of America.

I can't claim to have done proper experiments of my own though - I just see what works, and stick to it, or if it doesn't work, try changing it.

[edds]

I use an ericaceous fertiliser said to lower the water pH to 5.5 when I use tap water but I don't use this with rain water / RO / dehumidifier water.

[Herts Mike]

I repot most annually mainly to check on root mealy bug. Bigger stuff every other year.

They all seem to do ok.

[SimonT]

I don't think drinking water is supposed to come out of the tap with a pH of ~5.5.
I live in a soft water area, water is slightly alkaline and just use tap water for my plants, plus I use very dilute feed regularly- this seems to work.

[Jim_Mercer]

UK tap water should have minimum ph of 6.5 (see link below)
When I was able to lift watering can I did add white vinegar to lower ph, now my plants have to make do with what comes out of the hose

https://www.dwi.gov.uk/the-physical-and ... %20dosing.