Rotala macrandra won't get red

[maverick2402]

I have some Rotala macrandra in my 20 gal. tank and I can not get it to turn red .It gets sort of pink on the bottom of the leaves but just green on top.I add 2.5 ml of Seachem iron as recommneded on the plant chart on Seachem's site.Should I be adding more and what kind of trouble could I get into by adding more iron.I also added all of the other Seachem products as recommended on the chart.I understand that this lack of color could possibly be from a lack of enough iron and was wondering if anyone has any isight on it.Oh yea I am running a power compact light with a 10000k bulb thats giving me about 3.5 watts per gallon and pressurized CO2 at about 40 ppm.

 

[djlen]

Over-doing it with Fe can lead to algae problems.
What is your N level in the tank?
You definitely have enough light, at least to see some pink/red color, but excess N can inhibit red color in plants. Many folks, when they want to photograph or exhibit their tanks with reds in them, will cut the N back to bring up the reds.
If you do decide to cut back on the N be careful not to lose too much of your balance.

Len

 

[maverick2402]

How can I test for N. Is there any reliable test kit ?