AusBonsai

Hi Guys,

I ma reading several source on the pH of this diatomite being the problem and people saying it is too alkaline.

But whereas maidenwell diatomite is a pH of 5.5, mT sylvia, from what i can find, in only a pH of 6.

6 Aint alkaline the last time i looked.

Who has tested this diatomite, and how did they test it, with a pH test kit, dry, soaked in water and tested the water, with an electoric pH meter?

Want to get a definitive answer, because if it is indeed only a pH of 6, then why the hell are we looking elsewhere for the hard to find components like small particle scoria, expanded clay, or pumice that bloody floats hahaha.

Anyone who has experience with this and pH testing, i would be interested in any info.

Grants soil test thread covers this. From memory he got a high ph (well if 7ish is high) but then on retest it was about 6.

Dorothy koreshoff argues that ph is irrelevant when using a very open mix. She says its only when the mix is tight that the plants absorb acid/alkaline and ph begins to matter.

If you're worried, add some coco peat to your mix to balance it (its slightly acidic).

hey bio

i was asking the same sort questions as you are not to long ago
the responses i received were that there has been a lot of people using diatomite alone as a potting medium and have had great results, the only time it was OK was with some plants that like acidic soils like azaleas, apparently they will grow in it but wont thrive because the diatomite alone isn't acidic enough for it
a lot of people are adding zeolite to there diatomite mix's to hold nutrients in there mix

hope this helps

cheers
matt

Hi All
been using mt sylvia for a while now since maidenwell went out of business and found no difference as far as i can tell , but then i don't think i'm experienced enough to tell but trees are thriving in mt sylvia so i'll stick with them.
regards
peterb

Mt Sylvia's MSDS states that Kleensorb has a PH of around 8 while the raw diatomite has a PH of around 7.
Kleensorb is fired at around 400deg C to increase its absorbency, this also increases its PH from 7.? to 8.?
No doubt the quarry will cough up some variation from time to time but I prefer to stick with the MSDS for the right info.

As stated, you can add some other ingredients to buffer the PH until it reaches a suitable level.
Most plants will be happy in PH of between 6.5-7.

Yeah thats what concerns me, the MSDS shows such a high pH, but the testing grant did shows a low pH.

This is why im confused, and wanted some real world testing results and confirmation.

After using mt Sylvia for about 4 years now after Maidenwell went bust, like Peter I have had no issues with it over a long time, and in fact think it is better than anything else available
Doatomite and Zeolite is my mix for every variety from Azalea to Zelcova

As with Ken I notice no difference other than the fact I preferred the colour of Maidenwell. But seeing the mine has shut down it's rather a moot point - it's Mt Sylvia or nothing I think Maidenwell were skimping at the end as I found the bags were very dusty but the Mt Sylvia is very clean and consistent in size. I have planted trees in 100% with no dramas.

And what size are you blokes sifting the diatomite down to?

Bougy Fan wrote:...But seeing the mine has shut down it's rather a moot point - it's Mt Sylvia or nothing ...

Pumice?

I take out anything below 4mm - but don't throw it out and use it as a propagating mix and for trees like Swampies that like a lot of water as I find the smaller particles don't drain as well.

For me Scott it's a case of what's cheap and easily available as well as doing the job. I can go and buy bags of Mt Sylvia for under $14 at a local produce store. I can't find pumice at all locally and I doubt it would be at that sort of price.

I do love the fact that we have so many types of medium available to us there days

I do not sift at all, just use as comes from th bag
2-7mm
I sift when wash to re use tho. Take out less than 1 mm or so

Ken

hi scott,

you dont find that pumice works it way to the top when watering semi heavily and floats, stratifying the mix?

I have heard of others having this issue.

anybody know if it is available in s.a.-----all nurseries I ask don't know it-----all pet stores I've asked haven't heard of kleensorb

Try a produce store not a suburban pet store. It's sold as kitty litter in pet barn type operations. Some industrial supply stores sell it as a spill absorbent. It should be available