Hey I recently got a anubias from petco that is on a lava rock. I have had it for about 1.5 weeks and the leaves are starting to turn yellow. I have a few suspicions 1) need iron 2) too much light. My tank is a 1.5 gal tank with a led light on top, I also do not use fertilizer for the plant. I keep the light on for about 5 hours if that info helps. I would like some help to narrow down the cause of the plant turning yellow.
I would have to say that it's a lack of iron. . Since it's tied onto a piece of lava rock and you did not bury it, I would go with a nutrient problem, also try leaving your light on for longer hours around 8 ~ 10 hours per day.
You didn't specify the strength of the light.... If you're looking at anything 2+ watts per gallon, you've found your problem. Anubias prefer shade and will turn yellow even if you're pumping it with ferts under a high-light.
What I do in my high-tech 5 WPG tank is place a piece of cardboard under the light above the anubias to create shade for it. The nutrient concern is definitely still valid though. Since you're not planting it, you're definitely going to need iron (and possibly potassium) in the water column to keep the leaves from going yellow and dying off. Some excel would definitely help with growth if you're finding the growth rate to be too slow, too.
Well the lighting is the cluster of 9 LED lights from a tetra 1.5 gal tank. I dont know the specific watts of each to calculate the watts/gal but i know that is has to be relatively low since it is not a high end LED light (correct me if i am wrong). Any other recommendations on the brand of fertilizer you have had experience with?