Staurygene turn brown~~ common problem?

[bonjour82]

Hi folks,

I noticed my staurygene repens that have been blooming for some time recently started to have a patch of leaves turning brown and rotting away.

This seems to be a common problem for other aquarist when I google the web...

My tank specs are

- kH - around 2
-gH - 10
- CO2 - 2 bubbles per sec / 6 hours
-Lighting - Twinstar LED , 8 hrs per day
-Temp - 27 deg

Fert regime
- APT All in one fert - 2 times a week , 3 ml each time ( 45 cm tank)

I have a pic to show. Does anyone have similar experience with this plant and what could be the possible cause?

Thanks - Alex

[greenie]

My S.Repens lawn usually will melt if I sudden change light intensity to high or overdose Excel.
I have to keep my diy LED to lowest setting to make them grow healthy. If not they will "melt" in a week or two later.
They seemed to be an easy plant to propagate and based on my experience too much of nutrient and light they don't like. My CO2 is set unlimited by pH drop measurement, drop checker and normal monitoring of fauna.