linda mar wrote:

Hi Dave,

ok. I guess I need to add more iron then, to start (to get the plants more
green. the instruction says "as needed" so I don't have a good feel for
what would be enough, and I don't want to OD the plants/fish...)...

If you have a test kit, aim for 0.1 ppm. From rereading your posts, it sounds
like your Iron is already at 0.6ppm? If this is the case, the yellowing is most
likely not caused by insufficient iron!

Let's start from scratch. Please send us your test results for:

Nitrate
pH
KH
Iron
Phosphate (if you have the kit)

Also please send us:

Tank size
Lighting
Substrate
Water change schedule & water type (hard tap, soft tap, whatever you use)
Current fertilizer dosing
Fish load