Java Fern Problem, and More

[aquabillpers]

I can't grow Java fern in one tank. C. wendtii do just fine and have expanded their range to all corners of the tank; S. sublatta grows and spreads; vals and hygros struggle; the Java fern just melts.

The tank is a 29 gallon that has never been as successful as my other, shorter tanks, in which everything grows in abundance. But java fern has grown well in the 29 in the past.

My experiences with this tank were chronicled in much detail a year ago. Here's the thread: http://www.barrreport.com/general-plant-topics/4355-cryptocoryne-wendtii-allelopathy.html

My question is, why won't the Java fern live in that tank? I've searched the internet and found all of the usual causes of Java fern problems; none apply here.

It can't be that the crypts kill the Java fern, right?

Bill

 

[Gerryd]

Bill,

I remember reading one of the Amano picture books and he mentioned that in summer or high temps, that Java will die off considerably.

I have temps in the 84-86 range and my Java does well so not sure of the above

I have had Crypts and Java before I don't think that is an issue.

Are they getting too much shade? Do you fertilize at all? Maybe a pinch more ferts?

Hope this helps.

 

[TheKillHaa]

i think java fern likes potassium more than regular plants, not a fact, but will no hurt to test by yourself.

T.

 

[VaughnH]

Don't Java ferns have to get most of their nutrients from the water column? And, crypts have the option of picking up most of their nutrients from the substrate? So, if you dose the water lightly, but have a nutrient rich substrate, isn't it to be expected that crypts would do much better than Java Fern? Of course, I don't know if that is your situation.

 

[Tom Barr]

IME, java ferns are very tough plants. Their only issue is CO2/light.

I think in Bill's tank, which is non CO2, that the other plants are really dominating as growth ebb and flows with various species.

As they do, the scarce CO2 is used up........

In non CO2 planted tanks, you have a small pool of CO2 available.
This CO2 is very strongly competed for by the various species.

Some are much better than others.
Java fern does well typically in non CO2 planted tanks.
However, if you add a lot more species, many of which have reserves(like Crypts, those rhizomes are about 50% or more of the dry weight biomass- these serve as storage organs), those plants once established..............will use those reserves in the start of a growing season to get going and dominate/out compete based on total available surface area and biomass. the other thing is that when times are lean, later in the season.........then they have a back up and can flower, where the other plants are really hurting for CO2 or other nutrients.

The storage organs are mostly starch.......which is to say, reduced carbon........the ferns have little of this, often just sacrificing their leaves and the rhizome will sprout new leaves once the CO2 is higher.

So what to do?
Manage the growth, trim and keep the biomass consistent.

If you are a hands off gardener, then yes, much as DW's comment often state, she just watches the plants ebb and flow and phase in/out. I look at the system differently though and ask why that it is and then test and see what has been done research wise that seems plausible. So did she. However, The allelopathy argument does not hold much water.

I think CO2 is the without any doubt the biggest difference and we can easily test and see this in virtually all observations to date. Two big things suggest this:

1. When we add CO2, these types of issues go away and we can grow dense biomass, so with healthy biomass from all species, high production, should be not see evidence of allelopathy? It's just not there in any observations.

2. We may add activated carbon that removes specifically the allelopathic compounds. Again, same issue as ergo #1. No algae, no plant growth differences, help etc.

Why would Java fern do well without CO2, then when another plant starts growing well, the fern declines?

We can add nutrients, say like I suggest in the non CO2 article which is the water column based approach to non CO2, you can do that and know that the nutrients are not limiting strongly...........with aged sediments, this may.or may not be the case, also, Java ferns do not get any nutrients from the sediments do they?

So sediments are unknowns...........you cannot rule either way with them.

If you have soil/ADA AS or enriched sediment types, adding water column ferts in addition to them will help, we know it does not CAUSE ALGAE, WE KNOW THIS IS TRUE FOR NON CO2 AND CO2 ENRICHED SYSTEMS.
So............nutrients can be ruled out effectively.

What is left?

CO2 at a pretty low level, that's fairly hard to measure even with a CO2 meter.
CO2 is also the strongest limiting nutrient in any aquatic system except a few rich CO2 springs.

So this is the most likely suspect.
Not allelopathy.



Regards,
Tom Barr

 

[aquabillpers]

Thanks, all, for your comments.

Tom's comment about rapidly growing plants outcompeting the others for resources makes a lot of sense to me. Crypts, with their ability to store nutrients in their rhizomes, appear to be well suited for this.

I am going to remove all of the 30 or so crypts from that tank, replace most of the water, and start anew. I'll still keep crypts but in a separate room.

Bill

 

[Ghostie]

I also had a low light, non-CO2 20 gallon tank, but unlike you, I dosed the water column weekly with ferts. My ferns also started dying. I began adding half a cap of Excel daily when I feed the fish, and it has made a huge difference in all my plants. My java fern is even sending out new leaves. So now I know that CO2 was the limiting factor.

 

[aquabillpers]

Hi, Ghostie,

Thanks for your comment. However, in the past I have grown large amounts of Java fern in non-CO2 tanks, so much that I was selling it to local fish stores. I'm sure that adding CO2 would increase the growth rate, but in my experience the plant grows quite well without it (and without C. wendtii, too).

Also, I do add nutrients to the water column when testing shows that they are low. My tanks don't need much, though - maybe KNO3 and traces 3 or 4 times a year and maybe. PO4 is never needed.

Bill

 

[Tom Barr]

Thanks, all, for your comments.

Tom's comment about rapidly growing plants outcompeting the others for resources makes a lot of sense to me. Crypts, with their ability to store nutrients in their rhizomes, appear to be well suited for this.

I am going to remove all of the 30 or so crypts from that tank, replace most of the water, and start anew. I'll still keep crypts but in a separate room.

Bill

You might just trim them good and see the response, do not uproot, that will disturb things, just beat them back, you know they will grow back.
Slowly remove a few at a time instead.
Or trim say 2-4" sq each week and see if the Fern improves, just slowly modify the % biomass of the tank to slowly switch to a less Crypt dominated system.

If you do sudden changes, this may affect all the plants negatively.
As new shoots appear, add those new Crypts to the other room/tank etc.
Then keep hacking it back little by little.


Regards,
Tom Barr

 

[Tom Barr]

I also had a low light, non-CO2 20 gallon tank, but unlike you, I dosed the water column weekly with ferts. My ferns also started dying. I began adding half a cap of Excel daily when I feed the fish, and it has made a huge difference in all my plants. My java fern is even sending out new leaves. So now I know that CO2 was the limiting factor.

By adding the water column ferts, this likely also increased the CO2 demand, so this made the issue even worse.

This is one of the reasons from the old days why many thought excess nutrients = poor plant growth.

It was not direct, it was really increasing the CO2 demand even more by making nutrients independent.

When CO2 was accounted for, we no longer see poor plant growth at higher levels of nutrients. Even at low light and high CO2/nutrients, this is still independent of light, at high light, you have to have CO2 enrichment and richer nutrients. You still get good growth at lower light however with richer CO2/nutrients.

Balancing those nutrients and CO2 at low slow growth rates involves the plants themselves, but less so in a CO2 gas enriched system.

flow rates also decrease so access to the little CO2 is also an issue more so(?) in a non CO2 tank and as we have have seen, a lot in a higher light CO2 tank.

See? CO2 and non CO2 methods can teach the other pretty well and we see they are not that different, mostly the rate of growth is different and certainly the labor and inputs.

I'm not sure if Alan has the Excel like stuff ready yet.
Should be pretty cheap.

Regards,
Tom Barr

 

[aquabillpers]

Don't Java ferns have to get most of their nutrients from the water column? And, crypts have the option of picking up most of their nutrients from the substrate? So, if you dose the water lightly, but have a nutrient rich substrate, isn't it to be expected that crypts would do much better than Java Fern? Of course, I don't know if that is your situation.

Vaughn,

I think that there are suffficient nutrients in the water column. I do test and add when the numbers get too low, but that doesn't happen very often in this low light tank.

There surely are sufficient untrients in the substrate!

Bill

 

[Tom Barr]

Keep in mind that CO2 moves around and is much harder to rule out vs nutrients...which anyone can simply add and quickly rule out(say add 10ppm of K+ to rule that out, for a week, that should be plenty for a non CO2 system).

Cannot do this for CO2........

Regards,
Tom Barr