Martin,
I'm still learning a lot of this too, but yes you actually do want some
nitrates (5-10 ppm) in a planted tank. The plants use the nitrates for
growth. I've found that Flourish nitrogen will do the trick. In fact I am
having a lot better luck with the Flourish nitrogen then I was with the
source of potassium nitrate I had originally found. Although I'm hoping to
find another source as Flourish nitrogen is about $7.00 in my area for a
100ml bottle. If you want more info on plant fertilization have a look at
some of the writings at http://www.thekrib.com/Plants/Fertilizer/

Good luck,
Ron

"Martin" wrote in message
...
Ok, I have a big problem with this. For years I have been trying to get
Nitrates down (in smaller tanks) could not get rid of the stuff.

Now I have a 250l tank with enough light and CO2 injection and a 100%
Fluorite substrate. I now find that my Nitrates and Phosphates are low
(well
actually 0 and 0.25 respectively).

I find from posts I have read here - that I should be dosing with Nitrates
to get the plants to grow.......this is a jedi mind trick right!!!

OK, so if I have to put the bloody stuff back in......then....

What should I use?
How much? (for a 250l tank)
Can I get it pre-packed from a store (initially - until I get the
confidence
to make it myself).....
and more to the Point WHY do I have to?......I thought that by buying
Fluorite - the plants would have all they need straight from the
soil.....I
am loathed to put stuff into the water. In my opinion that is just asking
for algae.

I have Cabomba, Heteranthera, Vallis, Sagittaria, Eleocharis, 2
Echinodorus
Harbich

Thanks in advance

Martin - I can't believe I am actually trying to put Nitrates back into an
aquarium!!!!!!!!!!!!!!!!! This is mad - right.