View Full Version : Java fern mystery
I have Java fern attached to driftwood in two tanks: it grows fine in my 20 gallon tank, but in the 30 gallon, the leaves turn black or yellow and get holes in them. If I move the sick plants from the 30 gallon to the 20 gallon, they start to become healthy again. I have no idea what could be different enough between the two tanks to cause this. The 20 gallon actually has less light - 30 Watts per gallon - than the 30 gallon - 60 watts per gallon. I maintain both tanks the same way and use the same plant food in both. What could be causing the different results for the Java fern??
johnnyxxl
07-14-2004, 8:25 AM
I would be led to believe it could be lighting? I would think it could be the depth, causing less light to reach the plant, But I am not an expert
beviking
07-14-2004, 9:52 AM
What other plants do you have in each? If you have faster growing plants in the tank with more lighting, they could be robbing the fern of nutrients (actually using the nutrients up quicker than the fern can).
Is one tank closer to the television? The electromagnetic waves could be...ha ha no. Just got a little silly.:D
Captain Hook
07-14-2004, 12:15 PM
Same thing happened to me when I bought a piece of wood with java fern on it. When I took it home I put it in an unheated tank so I think the temp difference could have caused it. That or possibly too much ammonia or other nutrient.
anonapersona
07-14-2004, 2:52 PM
The regular java fern in one tank seems to do better when the DIY CO2 runs out. The narrow leaf java fern in another tank is beautiful in high CO2, constant, pressurized.
The only way I can explain it is that perhaps it is the changing conditions that it does not like.
Well, I have some floating plants, including duck weed, in the 20-gallon tank, and there's a plastic bottle (cut in half) under the outlet of the Penguin 170 filter, which I put there to reduce the surface agitation. I have two Pearl gouramis in that tank and wanted to see if the male would build a bubble nest. The 30-gallon tank had nothing but Java fern until a few weeks ago, when I added Java moss because the fern was looking so sick. But the problem in the 30-gallon tank exixted for months prior to my adding the Java moss.
Since I'm not adding CO2, I didn't think the surface agitation would have much effect on the plants. I'm just curious whether the problem has to do with too much/too little light, too much/too little nutrients, or something else entirely.
beviking
07-16-2004, 9:57 AM
I'd be inclined to think nutrient deficiency if it isn't just a reaction to tranplanting it (if you recently moved it into the tank it may go through an ugly phase before it starts growing nice again).
I have some j fern in a 5 gal bucket, in the basement with no light that looks good (been there for 2 months). It hasn't grown much if at all. My Java fern in my main tank gets good light and CO2 injection and is getting too big for my liking. It too looks good.
It's the ratio of light to nutrients that's important as well as the presence of either.
I've had good results adding extra Potassium (K) when holes start to develop (which is usually a week after I didn't add any xtra K).
daveedka
07-17-2004, 6:23 PM
I was thinking nutrients as well, this seems to be a low tech set-up you are talking about, what are you dosing as far as ferts if any, and what is the difference in fish loads waste etc. In my low tech set-ups (I don't do high tech) the J fern grows much better with a little K supplemented, and in the tank with the least plant to fish ratio. in other words it does well with more fish providing ammonia and nitrates. But it really didn't do extremely well until I started dosing K. in my big tank, there is J fern at every level. in a 31" tank there is quite a difference between light at the top and bottom. there doesn't seem to be any difference in growth or plant health with the J fern though.
I am adding Leaf Zone, which contains iron and potash (K2O). I assume the latter is an adequate source of potassium. I didn't add any to the larger tank for a few weeks because there was an algae bloom. But I think the problem predated that anyway. Anyway, if I can grow a plant in one out of two tanks, I figure I'm batting .500.
daveedka
07-19-2004, 4:29 PM
Just curious, what are the fish load difference For the purpose of N. in my low tech tanks, I supplement K based on The N produced by the fish, my guppy tank uses a lot more than my 115g.
.500 batting average isn't bad, but higher would be more fun.
beviking
07-20-2004, 9:56 AM
Just out of curiosity daveedka, do you have a formula for N:K ratio or just add more K if N is up, less if it's down?
30 gallon tank:
4 boesmani rainbowfish
3 green swordtails
2 platys
2 corys
1 yoyo loach
20 gallon tank:
2 pearl gouramis
4 small platys
1 cory
1 yoyo loach
The 30 gallon tank, where I'm having trouble with the plants, has the higher fish load. So maybe I should use just K instead of the Leaf Zone?
beviking
07-22-2004, 9:49 AM
I would add the K in addition to the leaf zone and see what happens after a couple weeks. K is one of the macronutrients and is used in greater quantities than the micronutrients in the leaf zone.
OK - where can I get plain K? The local fish store only has Leaf Zone and similar products that contain potash, Fe, and other nutrients. Or should I get Flourish?
Thanks.
daveedka
07-23-2004, 10:13 PM
For just plain K, Use nu-salt or no-salt, I use Nu-salt, which is KCL + less than one percent other stuff. I dose 1/8 TSP twice a week in the 15g and the 10g, haven't sttled on a dose for the big tank yet.
Just out of curiosity daveedka, do you have a formula for N:K ratio or just add more K if N is up, less if it's down?
I wish I had the ratio worked out, but essentially I just increase the K when the nitrates don't all dissapear (I know, sloppy science) I found before I started dosing K that At the end of a week I had about 15-20 ppm nitrates in the guppy tank (heavily planted) and 20-30 ppm nitrate in the cichlid tank (moderate to light) My tap water delivers 2 ppm P so I just staarted dosing K and and adjusted it to where my nitrates stay at 5 ppm and my P almost dissapears in a week. I am doing everything in my power to avoid high tech tanks, but just can't seem to stop myself, I'll be building a co2 reactor for the guppy tank the next time I have a week that I don't travel. I'm also going to start dosing KNO3 soon so I'm sure everything will change.
Is nu-salt sold in supermarkets as a substitute for NaCl? I assume at such low doses it's not harmful to catfish or other bottom dwellers (unllke aquarium salt)?
beviking
07-28-2004, 10:00 AM
Yes and yes.
I was surprised at how much the stuff cost. It was $5 for a dinky little can. The hardware store had a 40lb bag of KCL for water softening for $7.
Thanks to all for your advice. I like the way people on this forum go out of their way to help others, including novices like myself. Here are some things I've learned that plants need:
- Phosphate - they're going to get a lot of that from fish food, and too much causes algae growth. Maybe I don't need to add more?
- Nitrate - they'll get a lot of that from fish waste, but enough? I should test for nitrates to find out.
- Potassium - Definitely I should add this via KCl, or, if more nitrates are required, via KNO3.
Thanks again.
I've been dosing both tanks with KNO3, but it doesn't seem to make any difference. The Java fern in the 30-gallon tank still gets black leaves - see the attached photo. Is this algae? The Java fern in the 20-gallon tank has a couple of brown leaves, but doesn't look nearly as bad.
beviking
09-30-2004, 10:01 AM
I am doing everything in my power to avoid high tech tanks, but just can't seem to stop myself, ...
You know its going to happen, you resist, but it just keeps happening. I know all too well!
Paul, check here...
http://www.csd.net/~cgadd/aqua/
there is a plant deficiency chart (if you haven't found it already through other threads) that may help. You should dose K(potassium) via KCl (or K2SO4) along with KNO3. Potassium is used in greater quantities and, even at higher doses, isn't detrimental to your tanks inhabitants. Try it for a month because J.fern is a slow grower (relatively). In the link I provided, there is also a dosage calculator to help with how much of what to dose.
No, it isn't algae.
Leopardess
09-30-2004, 3:47 PM
The picture that you included looks, to me, to be exhibiting normal old age.
java fern is very unpicky about its water parameters and is really one of the last plants I'd suspect to show nutrient deficiencies...
Beviking and Leopardess,
Yes, I have looked at Chuck Gadd's nutrient deficiency symptoms page, but none of the symptoms included leaves turning black. Brown or yellow, yes, but not black. I guess the black leaves are just old, but I still don't understand why I don't get black leaves in the other tank. I'll continue dosing KNO3 - my nitrate readings in both tanks are 0, but I don't know if that's accurate.
Thanks.
beviking
10-01-2004, 9:40 AM
I agree with Leopardess that the pic looks like old age. However, my J.ferns were exhibiting a fair number of leaves like yours until I began CO2 injection and dosing ferts. I dose KNO3 AND KCl and the number of leaves per plant that look like h3ll is minimal if any. Maybe it's the CO2, but I believe it's the balance of nutrients. I know it's contrary to Tom Barrs sticky (and I don't advocate practicing against Toms advice!), but I've read too many accounts of added K apparently fixing "the problem".
I'm beginning to feel like a broken record... :o
OK, I'll keep experimenting with dosing KNO3 and maybe KCl too. I have the feeling that CO2 is the real answer, but I am trying to avoid going down that road.