Elodea Rot - Any Ideas?

[Gruntle]

HI all,
 
In both of my tanks I'm trying to establish a decent array of plants. I have had great success with Blue Stricta and Java Moss. I have an Amazon Sword in my smaller tank that seems to be going quite well, although my BN Plecos treat it like a snack bar and turn the outer leaves to lace (but I kind of like that).
 
My problem appears to be with Elodea. I have purchased some from a variety of LFS in my area, for the same result. The plants seem to grow well for a couple of weeks and then the stems toward the substrate just go brown and dissolve, leaving some very healthy green tips floating in the top of the tank.  My last batch has left my smaller tank in quite a mess with dead leaves floating willy-nilly through the current and bits of stem lying on the bottom.
 
I've tried burying a good 3-4" of the stem into the substrate (thinking somehow that a difference might be made) but I get the same result. I've tried burying the first couple of inches of the green tips in the substrate, the plant grows about 6" taller and then the lower part dissolves.
 
Is there a simple fix, or should I try a different species of plant? I'm not that keen to strip the tank every weekend so I can collect the dead bits, replant and start again for the same result.
 
Thank as always.

 

[frapadoodle]

Elodea is more of a cool water plant. And can be quite finicky.
I would suggest trying another plant, or if you really like the elodea try finding the narrow leaf variety, it puts up with more abuse.
And while not a scientific observation, just an opinion, the quality (at least what I can find around here) has gone downhill.
On another note Amazon swords in smaller tanks are not good ideas. They tend to get massive, as well as having massive root systems.

 

[Byron]

I concur on the temperature.  There is also light; although said to be lower light, Elodea is still a stem plant and as it grows the growing tip is obviously closer to the light so the lower portions can die off.  This is the case with all stem plants, and if Elodea is failing, the others likely will too.
 
Stay with plants that will manage under the conditions you provide,meaning light, nutrients and water parameters (includes temperature).  If the sword is thriving, look for the chain sword; it is smaller and once established will send out runners and carpet the substrate if you let it.  A lovely plant in smaller tanks with moderate light.  Corkscrew Vallisneria might also work, unless you have very soft water; it too sends out runners but grows taller than the chain sword.
 
Byron.

 

[Gruntle]

Thanks all.  So in summary, my smaller tank is too tall for Elodea to grow effectively, plus being tropical tanks the water is too warm. I'll start looking for something different.
 
I'm happy now, I thought I was doing something wrong, but the fish are healthy and that's all that counts.

 

[Fish'nchips]

Need good flow too. It's the flow that delivers nutrient and carbon dioxide to the plant.

 

[mark4785]

Aren't there two kinds of Elodea, one for the cold water and one for the tropical aquarium?
 
I have Elodea Densa in an aquarium with a temperature of 31 degrees C. To get them to grow you need to avoid putting them into co2 'dead zones' as they have the potential to grow very quickly or die very quickly. Also consider that Elodea densa do grow horizontal shoots from the main stem of which can themselves deprive the middle parts of the plant from getting nutrients and co2 so you need to position the plant correctly and prune it often too.

 

[Byron]

Aren't there two kinds of Elodea, one for the cold water and one for the tropical aquarium?
 
I have Elodea Densa in an aquarium with a temperature of 31 degrees C. To get them to grow you need to avoid putting them into co2 'dead zones' as they have the potential to grow very quickly or die very quickly. Also consider that Elodea densa do grow horizontal shoots from the main stem of which can themselves deprive the middle parts of the plant from getting nutrients and co2 so you need to position the plant correctly and prune it often too.

 
To answer your first question, maybe.  Aquatic plant nurseries do develop new strains/varieties/hybrids of aquatic plants that can be more suited to aquarium life.  I've no idea if this has been done with the subject plant.  But I will say that there are six accepted distinct species in Elodea, but there are also 16 accepted genera in this family Hydrocharitaceae, and many of these genera are very similar in appearance.  The genera Egeria and Elodea are frequently confused, as the following attests.
 
With respect to "Elodea densa," this species is in fact Egeria densa as described by Planchon in 1849.  In her book Aquarium Plants, Dr. Christel Kasselmann remarks that this species is difficult to distinguish from the genera Elodea, Hydrilla and Lagarosiphon, and that Egeria densa is also a cold water species but seems to tolerate warmer temperatures "only for short periods."  She has collected it in Japan in water having a temperature of 30C, and in Argentina in water with a temperature of only 12C.
 
Byron.