I think it would help to start adding some plant supplements like potassium
and trace elements because it seems that your plants are limited by those.
With enough CO2 and good lighting, as you have, your plants should probably
be able to deplete the water column of nitrate, and yet you have 20 ppm NO3
in your tank without supplementing it. If the plants are lacking even one
nutrient, they cannot absorb any others. It is in those conditions where
algae commonly thrives. For potassium, use K2SO4 or KCl. For traces, Tropica
MasterGrow and Flourish are great. After you start adding those, the plants
will start to remove the NO3 and possibly the PO4. In that case it'll be
necessary to start dosing KNO3 and perhaps KH2PO4. There are many sources of
these chemicals discussed in this newsgroup's Google archive.
__
Alex
pcalex (at) hotpop.com


"Doug Sheely" wrote in message
...
My tank has been set up for about two years but I just added the plants
and
new lighting within the last couple of months. I am not adding any
fertilizers and I do have a UV sterilizer running after having a serious
green water outbreak approximately 2 weeks ago.Plants include Amazon
Swords,
Camboa, Ludwiga,Micro Swords and others.