Ammania lower leaves going brown

[Easternlethal]

My ammania's lower leaves usually go patchy and brown, sometimes glass-like. I usually pinch them off and everything is fine. But is that normal? I'm wondering whether it's too much iron or ammonia burn. Unlikely because i do not dose much iron and ammonia is 0 - 5ppm.

 

[sciencefiction]

It can't be iron. Iron is a micronutrient bleaching new growth if deficient. It will not affect older leaves. I don't know what iron toxicity would cause but I doubt it would affect lower leaves.
I'd guess the issue could be either macro nutrients such as nitrate, phosphate, potassium or lack of light/co2/flow.
Why do you think it would be ammonia burn? Plants consume ammonia. It's unlikely you've got extreme ammonia levels in the water column that would affect plants in any way.

 

[Easternlethal]

yea I think you're right. It's most likely flow/co2 because my ammania forest is quite dense. I have strong flow going over the plants but am not sure how to get it to penetrate the thicker areas.