Thanx for the info, kush and all others.

We have really soft, high pH water out of the tap here. Even if i use
that phosphate filled ph-Down stuff, the ph rises again anyway after a
few days. I have never had my tank acid! I have spent some time
investigating this phenomenon (the tendency for the pH to rise) and my
current theory is that its being buffered to a higher pH by the water
conditioner i use (these blue crystals, sold in australia by 'bates pets
paradise'). Im still unsure though. i tried removing all the rocks in
the tank, thikning they were affecting the pH, but it made no
difference: the tank just tends to increase in pH.

The 'pongol' im talking about is this stuff:
Ophiopogon japonicus, which is also mondo grass.

http://www.tropica.com/productcard.asp?id=159

and the dwarf variety

http://www.tropica.com/productcard.asp?id=159A

which makes it sound like a rather lame aquatic plant anyway.

"Can be used as a decorative plant, but only lasts a few months."

Bah! I'll sue the crap shop i got em from!

n

kush wrote:
Nick L-S wrote ...

the tank has an undergravel filter, which i hear isnt good for plants.


Sure it is. Different plants will do better with or without a UGF, though.
Deep root feeders like amazon swords and crypts do better without a UGF,
most plants don't matter, and stem plants - plants which send roots out at
the leaf nodes - seem to do better with a UGF.


My question is, does pH matter? The water here has a naturally high pH...


Yes, pH matters, but so many other factors affect pH that it's less
important than a number of other things initially like, probably, gH and
kH. As your tank becomes established the pH will tend downward. I use DIY
CO2 and a lot of driftwood or bogwood in my heavily planted tanks so that,
although the pH of my household water is about 8.0 out of the tap, the pH in
my tanks is usually around 7.4.


but if i try and use pH-down...


This is a phosphate-based product. It may not lower your pH but it will
give you SUCH an algae bloom!


All the plants seem to be doing OK except for some long and dwarf
pongol, do these plants need special treatment? Im currently not using
any sort of fertilizer, but i am thinking i will....


I don't know that name. Do you have the Latin?