Breakdown of Potassium Sulfate

[Lukara]

Hi, I went to the local hydroponics store today and got some Potassium Sulfate. I took a look at it, and saw that it is a fine white powder. On the label, the breakdown says the following:

50% Potassium Sulfate
42% Potassium
18% Sulphur
46% Sulphur Anhydride

What is Sulphur Anhydride? I've been looking this up and from what I've read it is another name for Sulphur Dioxide??? If this is right, isn't this dangerous? I would appreciate the input of your professionals out there. Also, I would appreciate the breakdown of what is contained in the potassium sulfate which you use so that I could compare with what I find.

Thanks in advance!

 

[djlen]

If it says K2SO4 you're good to go. That's what many of us use.
As to an explanation as to what the other ingredients are, I'll leave that up to the "professionals".
Len

 

[2ManyHobbies]

Don't worry about it. Sulfur dioxide and and sulfur anhydride are clearly not the same thing. It seems weird to me why they would use this noemnclature. Just easier overall to keep the naming simple. The thing that I would be more worried about is the listing for 42% pottasium. Pottasium metal reacts violently with water to produce hydrogen and pottasium hydroxide. A buildup of the hydrogen can explode when triggered from a spark resulting from the potassium/water reaction. I did not quench a still completely in the lab during gradschool and had a 'bit' of an accident that could have been VERY bad. I got lucky on that one.

In other words nomenclature is can be confusing if not used correctly. So if you are having to name something be sure it is correct! (This is probably more than you wanted to know!)

Hope that helps!

 

[Tempest]

I'd have to look at a label to see why they were listing the chemical that way but I think you can rest assured you won't be getting pure potassium metal because it would be way too dangerous to package it that way for public use. I'd say the lsting on the bottle that way was for some agricultural use so as to make calculatons of equivalents.

 

[wetmanNY]

A label translation. What you have is 50% Potassium Sulfate, which is a compound composed of 42% Potassium and 18% Sulphur, because of their respective atomic weights. The Oxygen atoms in the sulphate have not been considered.

The 46% Sulphur Anhydride will form some dilute sulfuric acid when it's mixed in water-- that's what anhydrides do-- which your buffer will neutralize.

Is this hydroponic formula specifically for countering alkalinity in water perhaps? You'd want a hydroponic solution that has a lowered pH, to keep some nutrients soluble. Not all hydroponic techniques can be uncritically applied to aquariums, however.

You're getting a lot of sulfur that you don't need. Sulfur in the aquarium comes from the breakdown of proteins, such as in fish flakes. What the fish can't process gets passed through and into the system in feces.

Personally, I use KCl, so I get some unnecessary chloride ions.

 

[Lukara]

Thanks for all your replies. I got a bit worried to use what I got and went back to the store and got a refund. I can't believe how hard it is to find Potassium Sulphate! I must have spoken with at least 10 pharmacists and 5 hydroponics store owners, none of whom have it.

I went to another hydroponics store and they had some potassium sulphate, however, their label was computer-generated (like hand-made). It says Potassium Sulphate, but doesn't specify anything else. I inquired about it, and the person at the store swore up and down that it was pure K2SO4...

Is there a way to be sure that it is pure?