Re: Water quality problem

From: Chris Teichreb (
Date: Wed Nov 03 1999 - 16:09:39 PST

Date: Wed, 3 Nov 1999 17:09:39 -0700
From: Chris Teichreb <>
Message-Id: <aabcdefg3690$foo@default>
Subject: Re: Water quality problem

Hi Chris,
>I am having serious problems keeping my water's Ph down for some
>aldrovanda I am growing. At first I kept the plants in some old
>aquarium water that had a Ph below 6.0 (my test kit didn't read that
>low), But within a week the Ph jumped to 7.6, which I assumed was
>because of some buffering capacity of the water, which originally
>came from tap water. So I switched to rain water. Same problem.
>Finally a few weeks ago, I started buying distilled water. At this
>point I set up a little aquarium for the plants, starting with a
>layer of peat moss covered by plastic aquarium gravel. I also added
>other plants such as Utrics, Salvia, and water Hyacinth. Still no
>change. My water starts off acid, then goes alkaline. Last night I
>redid it all again, except I left out the peat moss and gravel, and
>overnight it jumped from 6.6 to 7.0. I'm stumped.
>I have only one theory left. The Salvia and Water Hyacinths came
>from a small bucket I keep outside and filled with tap water. I
>know the Hyacinth at least is supposed to be very good at taking up
>nutrients and pollutants from the water, so I was wondering if they
>might be somehow leaching minerals back into the aldro. water now,
>which might react to raise the Ph again. I have taken them out in
>case I might be right.
>Does anyone have any ideas? Last week my tank actually turned green
>altogether, and the aldros. suffered quite badly from it. I only
>have a few bits of growth points left, so I really need to get this
>situation under control as quickly as possible.
>Chris F.

        Switching to rain water was a good step, for the exact reason you
stated. Buffering capacity of the water may make it difficult to reduce
the pH. So, assuming that the rain water is relatively free of dissolved
solutes, it should have a pH of 7.0 (neutral). What I would do is put in a
box filter with a bag (can be made from old nylons) of peat moss, and run
this. The pH should drop within a week, you just need to give it a chance,
and remember to replace the peat regularly.

        Aquarium gravel sold in stores is generally inoculous and should
not affect the pH, especially the plastic coated variety. The other plants
should not affect the pH greatly, unless they are dying and releasing
compounds/nutrients back into the water via decomposition (make sure to cut
off all dead or dying parts).

        The fact that the water in your tank turned green (algal bloom)
indicates that there are in fact high enough levels of phosphorus and
nitrogen to support their growth, and that these nutrients are originating
from somewhere. Perhaps the container you're collecting your rainwater in
is leaching out nutrients? This could be true if you're using a wooden,
untreated container.

        Finally, Aldrovanda can be a finicky plant to grow at the best of
times. The best advice when setting up any planted aquarium is to use as
big a tank as you can afford (buffering capacity in terms of pH,
temperature, etc.) and allow the tank to cycle and adjust completely before
adding the Aldrovanda. This means first growing fast growing, cheap plants
to remove excess nutrients and to attain a balance in the aquarium. It may
be up to 2 or 3 months before the tank is truly ready for the Aldrovanda to
be added. This is why it can be hard to grow, since most of us don't have
the patience to wait (I know I'm one of them!).

        If you want to find a ton of info on cultivating aquatic plants,
which I believe Aldrovanda and the aquatic Utrics fall more into this
category then into cp's when it comes to cultivation techniques, I'd
suggest starting at Tons of plant info and links. Until
then, hopefully your plants survive to grow another day!

Happy growing,


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