On 27 Nov 2003 10:52:40 -0800, (Nick D) wrote:

Does anyone have any ideas about how to reduce GH without affecting
the PH? I have too much Calcium and Magnesium in my tap water and
would like to reduce it without compromising the PH levels. My GH
right now is 10deg, which is roughly 180-200ppm. I think this is too
high and it is also affecting my plants as high concentrations of
Magnesium/ GH block the uptake of Potassium (the reason my plants are
yellowing in an otherwise healthy tank.)

Hi,

Jumping in, and I *could* be wrong here, but I don't believe that high
gH is your problem. kH or Carbonate hardness is what effects pH. I
also wonder about your reported dkH level of 11 and a pH of 7.0?!
Either you are injecting CO2 (and too much at that - those values work
out to 33ppm - enough to kill fish), or your kits are not reading
correctly.

Sounds more like a nitrate deficiency to me, or possibly low light
levels - or both! I didn't see ANY nitrate ferts listed in your list
of additions. Two twenty watt tubes is generally not considered 'high
light'. Add some macro fertilizers, either $tore bought or homemade.
Trace mixes are just that - trace elements, not macro element
fertilizers.

Don't laugh, I am serious here - but I use a mix of stump remover,
no-salt and fleet enema for my macro nutrient supplements. In your
tank, this would work out to somewhere around 1/2 tsp of potassium
nitrate, 1/4 tsp of no-salt, and 1 ml of fleet enema.

Swords are heavy root feeders, and generally do better with ferts
added to the substrate around their roots. They generally need high
light levels as well. Also, many plants sold in chain pet stores are
not true aquatics. For instance, many plants sold as Amazon
(Brazilian) Swords at PetSmart are actually Spathiphyllum - NOT an
aquatic, but a house plant known as Peace Lily or White Flag. They
will slowly rot underwater - be sure of your plant IDs.

Here is a link with a pictorial library for IDing your plants:
http://www.tropica.com/plant_print.asp

Try the Krib for general info:
http://www.thekrib.com/Plants/

Another good plant link with detailed info on kH, pH and CO2 levels:
http://www.csd.net/~cgadd/aqua/

And try some crypts, they will do great in your tank at it's current
light levels.

Good Luck,
Greg