anubias turning yellow
My plant tank has been set up for roughly 7 weeks. All the bunch plants and
swords are doing well. However, despite the fact that they are growing new
leaves (two have also produced flower stalks), the anubias leaves are turning
yellow. The new leaves are also quite yellow, and don't appear to be turning
The anubias are an assortment of nana, barteri, coffeafolia, bangkok, and
congensis. The nana and bangkok appear to be suffering the most. All were
bare root and I assume grown emersed.
I use Dupla fertilizers, and maintain iron concentrations of .1 to .2 ppm. GH
is 3, KH is 3.5, and I use CO2 to maintain a pH of 6.8 - 6.9. I do weekly 30%
water changes with RO water reconstituted with 1 tsp/10 gallons synthetic sea
salt and calcium carbonate. My well water has GH of .5 and KH of 24, so I
don't mix any tap water with the RO. Nitrates and phosphates are undetectable
in the tank and I wonder if the anubias are suffering from a lack of nitrogen.
There is a fairly large fish population and I feed well so my assumption is
that the hygro and other fast growing plants are consuming all the ammonia etc.
that is produced.
Is this normal for emersed grown anubias, or is it possible that the lack of
nitrogen is responsible? If it is a lack of nitrogen, what would be an
effective method to increase the level? I skipped the water change this week
to see if the nitrate level would increase a little.