Hi niko,
yes, this is a very interesting theme from me. I too knew this "myth" because i get out my tanks... i wanna believe iit, ... but i cann´t
too much = algae, welll, lets me see it.
I have always thought what recommend levels of iron was too much high. My experience with quelate iron (now i use Flourish Iron) is what levels>0,5 = algae. Water? balance N-Fe? i don´t know, i used tapwater with Kh 8, Gh24 and ph 7,4 (in South-East of Spain the water is very hard).
The substrate is a older mix of other tanks, with 90% fine gravel and 10% clay+MO+vegetable rest (and earthworm of my garden

). Like this
In
my personal page (in spanihs, of course) you can see other photos about progress in the last months.
Now, the first problem is the temperature, for the fishs not plants... my 300 w heater is ON all the night. For the plants the "problem" more serius is the period of light, because, for example, i think my rotala indica, after four moths submersed look like this:
just this plant in my tank inside home have fine and large leaves :-s ,
look the
limnophila aromatica
When the plant just go out of the denseness stop the growth and turning very slowly, i think this is blame of light period, but i don´t sure.
Other curiosus problem is the abrupt change between shadow and light.The plants suffer a soft whiten.This photo was make with flash from exposition control and white balance.
well, i think this is a minor problem.
Pd: i hope you can understand my english. :neutral: