You think youve got problems with rain ... today its -34C with a
20 to 30 mph wind from the northpole with ice for roads and no visibility
due to blowing snow ... half the schools are closed.
At any rate, Cabomba is difficult to grow. It has a high light
compensation point and cannot use bicarbonate. It therefore requires lots
of light, soft water and an acidic pH. I think your light is fine but
what is your pH? I have also read that Cabomba cannot tolerate water
movement but I dont put too much stock in that. Finally, I agree with your
assesment of the iron situation. I make my own chelated iron with EDTA and
FeCl3. You might also want to add the other micronutrients (Mn, Cu, Zn,
Co, B, Mo). It is my opinion also that Cabomba needs a rich sediment,
though you also seem to have that covered. What kind of soil did you put
in your one tank?