# Ludwigia Stems Become Very Soft and Melt Away



## LindaC (Nov 7, 2005)

For the past few months, the stems of any type of Ludwigia that I put in my 29 gallon tank turn black and very soft and then just die. Sometimes they start turning black and getting soft from the bottom up but I have had a lot that turn black and soft in the middle of the stem, while the bottom part and top seem healthy, but not for long. I just can't figure out why this is happening. 

This plant use to grow awesome for me. I had some narrow leaf ludwigia in my tank about a year ago, that grew like gangbusters and had the prettiest colored leaves and there was less light in the tank then there is now!

My 29 gallon has 65 watts of flourescent light over it, pressurized CO2, Flourite subtrate, and I dose ferts KNO3, Phosphate and Potassium. I also dose Seachem Flourish and occasionally some Seachem Iron.

Could it be that the Flourite has lost all it's nutrients? I have ordered ADA Aquasoil and powersand and plan on switching my subtrate over to this when I get back from a business trip next week. i have also ordered a second 65 watt bulb 6700K to go in my Current dual 2x65 watt satelittle fixture. So hopefully I can start growing some decent plants in my tank.

I would like to find out what is causing my stems to soften and melt away though, it's very annoying. I have also had this problem with my Rotala indica too, another plant that use to grow very well for me.

Any thoughts?


----------



## AaronT (Apr 26, 2004)

How much of the nitrate, phosphate and potassium are you adding?

The Flourite doesn't really have nutrients in it. It has the ability to bind with the liquid nutrients we add to the water column and make them available to the roots.


----------



## John N. (Dec 11, 2005)

I have a feeling that the light is not enough anymore because the bulb is old. It's possible that you just need to replace the bulb and you'll get that extra bulb intensity to help the plant grow better. 

-John N.


----------



## Briney (Jun 17, 2006)

the exact same thing happened to me and i tried EVERYTHING i tried iron in the water and soil, i tried cytokinins, i tried extra N P K nothing worked. the conclusion i came to is that my soil was just too old. i had it for 1-2 years at this point. replaced my soil with a Aqua Soil- Flourite mix and the problem stopped. Go easy with the Aqua Soil cause then it killed my Ludwigia outright because of a massive ph drop. those american plants dont seem to like it.


----------



## Freemann (Mar 19, 2004)

Well I had the same thing happening to me with the ludwigias, I did not change the substrate (flourite 3 years old already). The plants started growing properly again after I did 3 things lowered the light hours, increased iron to 1 ppm daily from both TE, single iron source, and lowered the NO3 from external source (KNO3) to 1,5 ppm daily (30 ppm reading in the water now) one of this 3 or all together helped ludwigias recover of the browning rotting of the stem. Now which of all it was, go figure, but I suspect it was the big increase in iron dosing.


----------



## LindaC (Nov 7, 2005)

I was dosing EI but found when I tested my water that my nitrates were always pretty high, I also have a pretty high fish load. I was dosing:

3/8 tsp KN03 3x a week
1 ml Fleet 3x a week
1/16 tsp of Potassium
5 ml of Seachem Comprehensive
50% weekly water change


I thought it could be the Fleet as someone suggested there was a lot of salt in it so I bought the dry fert Phosphate from Greg Watson, and do to my nitrates always being high at 30-40 ppms, I am now dosing:

1/8 tsp KN03 
1/32 tsp KH2P04 (P) 
+/- 1/32 Potassium
5 ml of Seachem Comprehensive

Once a week I add 1 ml of Seachem Iron too.

You could be right about my light not being high enough but I don't think I've had it for a year yet, can it burn out this quickly. It will probably be a year in the spring, off the top of my head, I can't seem to remember when I got my new fixture.

The thing is, I use to grow very nice Ludwigia under a 55 retro-fit from AH Supply that my husband sadly forgot to take the yellow paper off of when he set up the fixture. So for a whole year I was using this light with yellow plastic paper covering my reflectors. I didn't even realize it until I bought my new Current 2 x 65 watt dual Satelitte and saw the yellow plastic all cracked and embedded in the reflector. How sad huh?

It really is frustrating, I've purchased Ludwigia twice off of this site and also bought some at my LFS only to have the stems rot away on me.


----------



## AaronT (Apr 26, 2004)

I think Freeman man be on to something with your iron dosing. 1 mL per week is hardly any at all. You might try doing 1 mL per day and see if things begin to looks up.

I'm not a fan of EI either. It works for some people, but I prefer to dose according to what I observe the plants need.


----------



## Avalon (Mar 7, 2005)

Sounds like a lack of light to me. I've grown L. repens for quite some time, and black stems = lack of light. Once you get the light up, it can melt away again from a lack of N, but you won't notice the black stems--the leaves then stems just dissolve. I think many underestimate the amount of light this plant needs. L. repens is a shallow water, marsh type plant, and needs a ton of light, or be lying just below the surface to flourish. The 2x65w fixture should work for you much better. I didn't find 1x65w over a 29g to work very well with this plant.


----------



## Minsc (May 7, 2006)

I'm not convinced Ludwigia need much light, I have L. palustris flourishing under 1wpg in my 15 gallon. It did however melt in another tank when I introduced some crypts and they got crypt rot...

I dunno, make of it what you will


----------



## LindaC (Nov 7, 2005)

Ludwigia used to grow very well for me under 55 watts of light in this same tank, this is why I am so perplexed. It not only grew well but it had a nice copper tone to it as well, it was very pretty and one of my favorite plants. The same with Rotala indica, it use to grow very well for me, nice and bushy, not very pink but a sly hue was always present, now this plant doesn't grow well for me either. The stems do not rot like the Ludwigia but it stunts appearing not to grow at all or new leaves sprout out very small.

I'm sure that the new light and new soil will help tremendously. I do wish I knew why this was happening though.


----------



## hoppycalif (Apr 7, 2005)

May I suggest increasing your phosphate dosing? You say you have high nitrates already, and plants seem to need phosphate in order to use the nitrates. When I had a 29 gallon tank I was using about an 1/8 tsp of KH2PO4 every other day. If you try this, give it a couple of weeks to see if it works, and if not, you can always go back to the lower dosage.


----------



## LindaC (Nov 7, 2005)

I will give the extra phosphate dosing a try, thank you!


----------



## banderbe (Nov 17, 2005)

Yeah I am dosing 1 ml Seachem iron every day.

From what I understand iron is used up pretty rapidly. Another user on this forum (or was it planted tank?) did some tests and found that within just a day the iron he added was already gone. I think the user's name was Hypancistrus or something like that.

Also I would be careful about making dosing decisions based on the results of a test kit. When I have done that it always results in algae and unhappy plants. Unless you have Lamotte kits or something, it's better to just watch the plants.


----------

