On Mon, 5 Apr 2004 22:09:19 +1000, "Graham Broadbridge"
wrote:

"Cardman" wrote in message
.. .

BTW -- you should try to get those nitrate levels down. 100ppm is
definitely on the very high side where it will be toxic for at least some
fish species.

My fish can live in much higher levels perfectly fine, where they just
become unhappy in a world where algae rules. So they are very happy
with anything between 50 and 150 mg/l, when algae growth is very slow
at this level.

100 ppm NO3 is extremely toxic for freshwater fish, but of course any animal
can acclimatize to unsavoury conditions given time.

Well, even had I replaced totally all the water, then Nitrate levels
would exceed 100ppm in about a week.

In rare occasions when I am just two occupied with other things, then
it is algae that controls my Nitrate levels by explosive algae growth.

I'm not surprised that
algae growth is slow at 100 ppm Nitrates. Algae is opportunistic and will
find a better environment or hibernate.

Currently I manually remove it as much as possible.

A nice idea, but what you do not mention is that plants in fact use up
very little Nitrate, which is why I would have to bed plants very
heavily for any beneficial effects.

Plants use a lot of NO3 here. Given that your nitrate levels exceed 100ppm
I'm not surprised that you see no NO3 consumption.

My problem I am sure is half due to the Nitrate levels in my tap water
followed by more than a few fish in the aquarium.

The poor plants have no chance to even get started.

My plant problem is more a case of unsuitable plants for my former
water conditions and lighting, when those plants that are suitable do
very well.

Their problem then is mostly an algae one, where my Goldfish Weed is a
favoured sticking point for algae. And since this is difficult to
remove, then often some of the plant is removed with it.

I still have some of this plant growing in my tank, but either I need
to get algae and Nitrate levels in better control, or my new plants
will need to be algae resistant.

I'd suggest you reduce nitrate from your tap water to start with.

Yes, where now that I am aware that there is high levels of Nitrate in
my tap water, then so can I do something about it.

Keeping a good aquarium is all about such knowledge.

Cardman
http://www.cardman.com
http://www.cardman.co.uk