JAVA FERNS

[RYO]

Ok, i have several type of plant in my tank, cryptocoryne(lucens),crinum natans, limnophila sessiliflora but to name a few.Now i dont have too many probs with these exept my jarva ferns,they turn almost black, leaves go holeybut they do spawn jarva jnrs every where, is this the norm or is my tank too acidic for the fern.
tank params are-
ph - 6.2
nitrite- 0
amonia- 0
nitrate - 5 ppm
kh 17.9 ppm
gh 35.8 ppm
cheers for any help

 

[endparenthesis]

Does it happen with all the leaves all the time? Could it just be that some of the leaves were already getting pretty old?

The only time I've had a java fern blacken so far was when it had floated right up next to the light... and even then it was just a little part of the leaf. Is it up near the surface under heavy lighting?

 

[RYO]

It tends to be the older plants, as for the lighting its a 15W aqua-glo (cos its only a wee tank lol)and id say the ferns are a good 6-7 inches under the light