Vallisneria Rot

srozell

Guru Class Expert
Jan 24, 2005
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This is a link to some Vallisneria gigantea that was growing 3 meters long in my 120 gallon tank for about a half year.

http://www.barrreport.com/gallery/showimage.php?i=169&c=11

Over the past few months it's been dying back and as you can tell, it looks pretty ragged. In fact the leaves never make it to the surface of the water any more.

It is a soil tank with no CO2, but by the appearance of the problem I would suspect Potassium or Nitrogen shortage.

Any comments would be appreciated.

One would also suspect CO2, but I can not easily add CO2 to this tank.
 

darren_in_the_marsh

Junior Poster
Apr 14, 2005
15
0
1
San Francisco, CA
Re: Vallisneria Rot

i wish i could help, but i too have see this with my sword leaves. i think it is just a natural phenomenon when a plant stops growing. i would remove those leaves once they start to 'rot'; they are not doing any good for your tank, and in my case, cause me stress :( evertime i look at the tank. i would rather see an thinned out tank, that dying leaves!

darren

ps. get co2 in your tank, it really helps
 

GreenStuff

Prolific Poster
Feb 11, 2005
62
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6
Canada
Re: Vallisneria Rot

I've had that problem a few times and what I do is pull the plants up out of the soil just a little. If they're planted too deep they tend to rot. The crown of the plants should be at the soil surface.
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
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Re: Vallisneria Rot

That's not CO2.

That's nutrients like NO3/Ca/K+.

Soil last only so long. If these plants are 3 meters as you say, I assume they have grown in over time.

If so, then where did their nutrients come from? The soil. Have you added more nutrients since the start?

If not, the soil has run off of nutrients.

You can do a few things, add new substrate soil, tear the tank down etc.

Add jobes deep under the plants, add fresh soil "frozen mud ice cubes" under the plants. Add Flourish tabs(no source of macro's really).

You can switch to dosing the water column for nutrients also by adding KNO3 and some GH.

Add 1/2 teaspoon once a week for the KNO3, 1/2 teaspoon of the SeaChem EQ.

That will target most things. PO4 will express itself differently but you can add that later(1/8-1/16 once a week).

If you do small water changes, this will work fine.

If you do not do any water changes like a non CO2 method, add about 1/2 these amounts.

Regards,
Tom Barr
 

srozell

Guru Class Expert
Jan 24, 2005
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Re: Vallisneria Rot

Since I notice the issue I have beeen dosing KNO3 and KH2PO4 every two days, and Seachem Flourish every other day. (for about 3 months now)

I've been doing 1/4 water changes every week and adding K2SO4 at that time.

I also overfeed the fish in the tank hoping that helps as well.

These plants USED to be 3 meters, now none of the leaves make it to the surface before the rot starts.

As a side note, despite this tank being exposed to the sun, I have little algae in it at all.

I'll start adding Seachem EQ and see if that helps. Otherwise, any further comments would be helpful.

If that fails, would I be correct to assume that if I rip out my substrate, replace it with Seachem's Onyx, and CO2 and follow my regular dosing regime this problem should go away?
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
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Re: Vallisneria Rot

Well no algae, sunlight ans rot all point to low NO3/K.
Add a little, KH2PO4, SeaChem Eq and give things a few weeks to see.

I would not rush out and get CO2/onyx etc just yet unless you were already planning that.

Regards,
'Tom Barr