pure pumice?

[Rob]

Thanks very much both.

Our choice is really between pure pumice and pure moller.

Both have issues for us to work out.
for Sanicat it is a question of perfume, which is a major trigger for Alison's asthma, a full greenhouse of sanicat could well put her in hospital. I imagine the Europarts version has no perfume, can anyone confirm that for us please?

Cost comes in to it as well of course, how many pallets of Pumice would I need to pot my entire collection? - that isnt a question I expect an answer for here but something I need to consider if I can.
I think a bag of Europarts would go a lot further than a bag of pumice though, and may then work out cheaper.

I really want to get this worked out soon though.

[Herts Mike]

I'm with Nick_G on this and have half my Stapeliad collection and a few Aloes in Sanicat and they grow very well. The problem is watering as overhead just goes straight through and soaks everything below so I have to stand them in water and fertiliser in a couple of washing up bowls which is a bit tedious. They really need flood trays but I can't find anything that fits the shelf.

[Nick_G]

Wash the Sanicat before you use it. This should deal with any perfume and dust. I've never noticed any perfume to be honest but it is very dusty. I'm really not keen on the smaller sized stuff, Tesco or Europarts, seems to stay very wet for a long time.

[Tina]

Bob Potter, toobees sells pumice

[MatDz]

Thanks very much both.

Our choice is really between pure pumice and pure moller.

Both have issues for us to work out.
for Sanicat it is a question of perfume, which is a major trigger for Alison's asthma, a full greenhouse of sanicat could well put her in hospital. I imagine the Europarts version has no perfume, can anyone confirm that for us please? [...]

I didn't notice any scent out of the Europarts stuff, but it releases clouds of dust when washed (a pretty odd view, frankly speaking). I still have some, happy to post you a small bag for a trial!

I'm looking to buy some Sanicat, so should be able to compare both in a couple of days.

[MatDz]

Reporting back- though too early for any proper results- the seedlings potted in a mix of scoria and pumice, 50/50 [...]

Does scoria float the same as pumice? I find it pretty annoying (not to mention Perlite, never again!).

[ralphrmartin]

They really need flood trays but I can't find anything that fits the shelf.

My wife bought some trays to go under grow bags for tomatoes at a fairly reasonably price. Maybe something like that would do the trick?"

[mary44]

I buy pumice from this seller sun-of-india on ebay. It comes very quickly delivered by DPD I think it is. The packaging is a cardboard box with the pumice packed in a strong plastic bag inside. Occasionally the cardboard boxes are falling apart by the time they arrive but the shipment has always been intact.

The pumice is wet which makes it heavier. It is sold by weight. I have been using the 1 - 4mm pumice this year and the plants are looking happy and growing well in it mixed with John Innes. I have been potting lithops mainly. They sell different sizes of pumice and other grit etc. You can buy different quantities.

https://www.ebay.co.uk/itm/25-kg-app-32 ... 2856857562

When I can get it I also buy the bags of pumice from Ikea. I like to use this for seed sowing and use it straight from the bag mixed with John Innes, that also works well.

Our local Tescos still stocks the dust free cat litter and I sometimes buy a bag of that if I am running short. I haven't noticed much scent from recent bags. It used to smell really strong unless washed first which I don't bother to do any more.

Mary

[Chris L]

I have been considering pumice for some of my bigger plants (upto 7 inch pans/pots) this year as I am often worried [more so this year] about plants drying out (or not) at this time of year. We are being lucky if it is getting over 20degC in the GH most days.....

The two options from the seller mentioned above are (1mm to 4mm) and (5mm to 12mm). The box arrived in a timely manner and inside are two 12.5kg bags.

I decided to go for the latter as I was worried that the smaller size would be more 1mm than 4mm, thus like sand and too fine. However it seems that the larger size is way too big, most of the pieces being over 10mm, or even 15mm and a few at 20mm. Very few pieces are around the 5mm mark. There is also a bit, not too much of fine grit at the bottom of the bag. It doesn't look much like the stuff on the listing.....

So I've several questions now:
1) is this pumice (large image can be zoomed)?
2) do you think it would be best to get one of the smaller sizes and do a 50% mix of each?
3) do I add some gravel in to make it go further?
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[MatDz]

Looks like the pumice samples I have at home, assuming mine are pumice of course! Check if it floats (much less than Perlite, but still) and when submerged it should release air bubbles for quite some time. There might be more scientific methods, but this should be good enough.

On the size aspect, what about sieving through 10-12 mm sieve and crushing the rest?