Potassium

I see sulfate recommended, I wonder why. I have lots of stuff in my
water already, the only export capability I know for sulfate would be
conversion to H2S, or water change.

Why not nitrate, the plants could use it, or carbonate, which the
plants could use, or chloride. people are forever recommending adding
salt to the water, presumably for the chloride ion.

so, why sulfate?

In article ,
Charles wrote:

I see sulfate recommended, I wonder why. I have lots of stuff in my
water already, the only export capability I know for sulfate would be
conversion to H2S, or water change.

Why not nitrate, the plants could use it, or carbonate, which the
plants could use, or chloride. people are forever recommending adding
salt to the water, presumably for the chloride ion.

1) It's what's at the hydroponics store

2) It's what we've always done

Seriously that's always bothered me too. As you say there's no great
way to get rid of sulphate (and the stuff does hinder mosses) except
water changes.

If you're adding Potasium nitrate all the time it's unlikely you'd
need to add potassium. Adding K2SO4 is more for people that already
have high nitrates that presumably don't want to add (more?)
carbonate.

I would have thought carbonate would be the right thing to use, my
plants seem to have little trouble sucking co2 out of it if I
recognize biogenic decalcification. My water is hard as hell.


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On Sat, 11 Feb 2006 06:29:11 +0000 (UTC),
(Richard Sexton) wrote:

In article ,
Charles wrote:

I see sulfate recommended, I wonder why. I have lots of stuff in my
water already, the only export capability I know for sulfate would be
conversion to H2S, or water change.

Why not nitrate, the plants could use it, or carbonate, which the
plants could use, or chloride. people are forever recommending adding
salt to the water, presumably for the chloride ion.

1) It's what's at the hydroponics store

2) It's what we've always done

Seriously that's always bothered me too. As you say there's no great
way to get rid of sulphate (and the stuff does hinder mosses) except
water changes.

If you're adding Potasium nitrate all the time it's unlikely you'd
need to add potassium. Adding K2SO4 is more for people that already
have high nitrates that presumably don't want to add (more?)
carbonate.

I would have thought carbonate would be the right thing to use, my
plants seem to have little trouble sucking co2 out of it if I
recognize biogenic decalcification. My water is hard as hell.


Maybe I answered some of my own questions.

Nitrates are high enough, 40 ppm. That surprised me, maybe it's
because I added a couple of Jobe's sticks.

Carbonate is high enough, KH = 5.

One of the kits at the aquarium store did have KCl, they called in
Muriate of Potash, for quaintness sake, I guess.

Hydroponics store didn't have anything useful, all they had were
liquid nutrients and the guy there didn't know anything about them.

And, I found my 2 Kg jar of K sulfate in the garden shed, so I used
that. Not the whole jar, about a half gram.