Should Sulphate of potash look like this?

[tomotomotomo]

Hi all,

I recently bought 1kg of sulphate of potash from ebay and I think it has been mixed with something to bulk up the weight. The powder looks quite grey and what looks like dust/sand is left in the bottom of the mixing bottle.
I mixed 60g of the powder with 500ml warm water as per chuck's calculator

Before I go complaining, I'd appreciate some input as to whether this looks normal- I ask because I've never bought/used anything of the name 'sulphate of potash', just 'KSO4'.

Here's the link for the ebay page> NAKED GARDEN FERTILISER 1KG SULPHATE OF POTASH on eBay, also, Fertiliser Soil Improvement, Garden Plants, Home Garden (end time 22-May-09 21:50:41 BST)

Thanks,
James

 

[jonny_ftm]

My K2SO4 presents like sugar fin powder: very thin and splendish white. It dissolves completely if you respect the solubility as per Chuck's calculator. In no case such a black/brown depot should appear

From the link you mentioned, it looks like being some sort of not pure K2SO4, suitable for gardens but probably not for aquariums

 

[SuperColey1]

If you buy any powder there are different grades. Doesn't mean they are different concentrations or different products. Sulphate of Potash is the same no matter what grade.

The grade just means that there are different nominal grain allowances. For garden Potash then there will be 1-2mm pieces in it. For food grade it will be dust/powder.

Obviously the latter will be much easier to dissolve. I have the former and used to work for a major garden products manufacturer in the UK buying all this stuff in. I don't use K2SO4 anymore as there is plenty in the KNO3 and K2HPO4 not to need to add it. Mine is the same as yours

As to the sand/contaminants issue..........This is how it is stored. Remember this is to be used in garden products and therefore a little dirt doesn't matter:

On the left you see a bay that has about 5 tons in it and will hold about 50 tons of K2SO4. The floor may have half a ton of anything else on it. Then large shovel trucks (JCB/Manitou type) with 7 ton buckets will pick up a load, drive it to hoppers where it gets distributed to the production lines.

The floor has contaminants in it although the bay will only ever have K2SO4 in it. The trucks bucket will have been used to scoop up all manner of other garden products so will have remnants of Farm Manure, Soil etc. The hopper will have had a different product going through it on the previous boxing process.

This is all going to be used in the garden so contaminants don't matter. If you are on the unlucky side there will be 0.5% contaminants within the box. On average maybe closer to 0.05-0.1%

By the way for those interested in their cheap sand this is how dry/play/silver sand is stored:

There is about 50 tons in that bay and it will take about 120 tons. Process exactly the same, bay-bucket-hopper so same contaminant effects.

Saying this I use this dry sand in my tank and have done for years. I used the K2SO4 in the early days before ceasing to use it at all.

No worries of floor and buckets on KNO3, KH2PO4 as these are all stored in bulk bags but processed through the same large hoppers. Chelated metals are stored in 25kg bags on pallets and not the floor nor moved with trucks but the same process via hoppers although much smaller less dirty hoppers.

If you are worried then don't buy garden products. I'm not worried. I use it all

AC

 

[tomotomotomo]

Cheers for that people. It's reassuring to here from someone who worked at the source, and the pictures really put it into perspective. I've let the bottle settle and it looks much clearer, just a clear liquid with sand/farm manure at the bottom which I won't be disturbing anytime soon.
I'll post back if anything bad happens.
Thanks again.