[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

GH, KH and dissolving K2SO4

---------- Forwarded message ----------
From: psears at emr1_NRCan.gc.ca (Paul Sears)
Message-Id: <9703031518.AA23212@emr1.emr.ca>
Subject: Re: KH, GH   and dissolving K2SO4
To: Aquatic-Plants at ActWin_com
Date: Mon, 3 Mar 1997 10:18:19 -0500 (EST)

> From: "Scott Voldbaek" <voldbaek at circle_net>
> Subject: kH, gH, and Discus
> I do my water changes with RO water I buy at a local health food store
> treated with pH down and kH plus for the plants and to stabilize the pH.
	pH down is an acid (sulphuric, rather than phosphoric, I hope),
and KH plus is probably sodium bicarbonate.  All you are doing with the
acid is destroying some of the KH, so you can just add less of the KH plus
and forget the acid.

	HCO3-  +  H+  ->   H2O  +  CO2    (The CO2 leaves, maintaining
equilibrium with the atmosphere/CO2 system/fish/plants)

> My question is this, does raising the kH also raise the gH,

	Provided the KH-plus _is_ sodium bicarbonate, no.  Why don't
you use sodium bicarbonate from a store?  I'm sure it will be a couple
of orders of magnitude cheaper.

> and what is an
> acceptible gH for Discus.

	No idea on that one.

> Also, I'm using Sera kH-plus which causes the pH
> to go out the roof. Is that a common reaction when the kH is bumped up in
> really soft water.

	If you double the KH and leave the CO2 concentration in the water
the same, the pH will rise by 0.3.  If the water is really soft, the starting
pH may not be bicarbonate/CO2 controlled, and will be unpredictable, but
if you go for KH 4, you can use the KH/pH/CO2 tables to work out what your
CO2 concentration is after you have measured the KH and pH.

> ------------------------------
> From: nguyenh at nosc_mil (Hoa G. Nguyen)
> Subject: Dissolving K2SO4
> I have a question for the chemists on the list, as well as those using PMDD.  
> Will heating hurt any of the micronutrient or the
> chelation?

	It might damage the chelated ones.

> Would it make a difference if I heat just the K2SO4 (in water)
> and dissolve that first?

	That seems the best idea to me.

Paul Sears        Ottawa, Canada

Finger ap626 at freenet_carleton.ca for PGP public key.