Over the past year and half I've really had a difficult time with plants in my aquarium. For the first year my plants did very well, and then things gradually got worse. Just over a year ago I posted this: http://www.tropicalfishkeeping.com/a...ecaying-88601/
By last summer all of my swords have died along with the Anubias. I only have the Java Fern left, although I do have Water Sprite that does well.
I use about 2mL of Flourish comprehensive once a week.
I used a 6500K bulb up until maybe 7 months ago. I could not stop algae with that bulb, so I'm using an Aqua-Glo 18000K bulb. Just to be clear: for the first year of my tank I used this same bulb without noticeable problems. Switching to the 6500K bulb in my tank seemed to offer no benefit in plant growth but significant difficulty in controlling algae. As we know though, controlled experiments are difficult.
One modification I did try last year was adding some potash (potassium) to the tank. I didn't notice any difference. (However a few weeks after I used potash, all of my MTS mysteriously died within a few days - I'll leave that for a different story and hopefully not related to this discussion).
So I'm close to not being left any plants, with only the struggling JF left. I wouldn't say they have prodigious roots and I haven't seen any new leaves/stems for a few months.
Is there anything else worth trying, other than using the Flourish twice a week?
Water testing seems OK
KH 90 ppm
GH 107 ppm