Black spots on Java Fern Help!

[Geodiscus]

I have no idea would could be causing my Java Ferns to be having black spots on thier leaves. First thet are spots and later they rot out.I have been using flourish and have been injecting DIY CO2. Water parameters are 86 deg temp. hardness 120 ppm. carb.hardness90ppm. I have Cyrptocornes and anubias that seem to be fine(knock on wood). Ever since I got the ferns it has been getting worse.
Any suggestions would be appreciated.

[ChloroPhil]

It looks like you've got one or two of a few problems:

1. Not enough nutrition for the plants
2. A fish that chews holes in your plants

3. Both of the above- my guess.

Most Java Fern I've known will do well in lower light, but it needs good fertilization to maintain itself. That may be as simple as a high fish load vs. chemical supplimentation but they need food.

Also, looking at the rhizome, do you have a pleco or other largish rasper? I don't see much in the way of roots and that's usually the first to go with rasping algae eaters. Also, no roots = no way to feed.

My last guess is that because those also look like new plants you may be having an adjustment issue. Not every leaf will adjust well to submersion and may start dying off. Try floating the plants for a while rather than leaving them tied down at first. That should help solve #2 and 3.

[Wahter]

In my experience, both java ferns and bolbitis are sensitive wimps when there's a shortage of nutrients in the water column (as Phil/ bio pointed out). I've seen this in my tanks when I add a fast growing stem plant or a big sword plant into the tank with java ferns - the slow growing java fern gets out competed, develops rotting spots, and dies back. What other plants besides crypts and anubias do you have in your tank? The water where I'm at is soft enough, that I keep my java ferns only with the slow growing crypts, java moss, and bolbitis. I supplement with flourish iron (in addition to Tropica Mastergrow) and that's helped.

[Tom-ee G-ee]

I reather the use of hydrogrow tablet fetilizer....

It says to use one tablet per 40 Litres, but i place a tablet near a junction of plants so all are in close proximity to the nutrients released...

All i do is re-dose this sparse drop of tablets each water change (two weeks), in my discus tank, i stretch it every week maybe two like my other tank....

[browneu]

Black spots on the underside of Java Fern leaves are normal as it is part of their reproductive system. The holes and rotting out of the leaves are not. I doubt that a fish is eating holes in the leaves as Java Ferns have toxins as a defense mechanism. Also, they feed through the water column and not their roots so using root tabs will not be benificial for the ferns. It looks as if your tank could use some iron. Normally, in iron defficient tanks the leaves become lighter green and develope holes in them. Which is what I see with your Java Fern. I would dose with Flourish Iron and your problems should go away.

[jules]

Interesting - so the java ferns reproduce with spores just as houseplants/perennials?

[ChloroPhil]

Yep, those little brown spots on the underside are called sori or sorus (singular). They're groups of sporangia, their form of sex organs. Unfortunately, most ferns can't reproduce sexually underwater, so they have little use.

If you want to have some fun, put a bunch of fern in a soda bottle in a window and try growing it that way. When you start to see sori give the ferns a few good sprays each day and see what happens. If you want to get even more into it, use a small paintbrush to try spreading the spores.

These guys require water for fertilization, so you're not actually fertilizing the spores with the brush, but you're giving them a better chance of coming into contact with eachother. If it works out you'll have little gametophyte plants which will then put off gametes which, when fused, will become another fern as we know them. :)

Mosses can be cultivated the same way.