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Re: Ph Drifting Down Between Water Changes...
- To: Aquatic-Plants at actwin_com
- Subject: Re: Ph Drifting Down Between Water Changes...
- From: Dave & Robyn Wilson <rwilson at octa4_net.au>
- Date: Mon, 19 Feb 2001 08:43:36 +0930
- In-Reply-To: <200102182048.PAA20079 at actwin_com>
- References: <200102182048.PAA20079 at actwin_com>
>Date: Sun, 18 Feb 2001 11:51:55 -0500
>From: Paul Mouritsen <mourip at erols_com>
>Subject: Ph Drifting Down Between Water Changes...
>Over the last month or so I have found my average PH to be slowly drifting
>down. It used to be around 6.9 now it is 6.65. Here are some details.
>Tap- ph 8.2, kh 4, gh 8
>Tank- ph 6.65, kh 2, gh 8 (before lights this AM)(changed water yesterday )
Your tank is using alkalinity, buffering capacity or carbonate
hardness (KH) at a rate you can calculate. Try adding some
potassium bicarbonate to raise your KH up closer to or level with
your hardness (GH). To raise the KH 10ppm or about half a German
degree, which I think is the measurement you have used, add 20 grams
per cubic meter (1000 litres). You can use sodium bicarbonate as a
buffer but plants don't use the sodium. Potassium bicarbonate will
provide a potassium source for the plants as well as buffering
capacity. Potassium bicarbonate is a bit harder to find than the
other but worth the extra effort. Potassium bicarb is also about 10
times more expensive than sodium bicarb but you don't have to use
much. When you add the buffer the pH will rise so you may increase
the CO2 rate if it is not on auto. Plants are about 44% carbon dry
weight once you raise the KH they can get more carbon and will
probably start bubbling again.