Rotala macrandra v. 'narrow leaf' aka Rotala magenta

Let me see if i can do the link right

http://www.aquariumgarden.com/index.php?doc_base=listings/bunched_plants.php

They are very similar in shading in 'real life', but if you get some Magenta and figure out how to grow it, write back and let me know how you did it.
I've been battling this plant for months with little luck under 4watts/gal. and CO2 at 25ppm.
Sometimes you just have to realize that you can't grow certain plants, move on, and cut your losses. I think I'm at that point now.

Len

Thanks for the reply. I'm interested in trying out R. Magenta, instead of R. Macrandra, because if its smallers leaves more suited for a 20 gallon. If I'm unsucessful, I'll cut my losses too and score some Macrandra from the LFS.

Rotala macrandra var Narrow Leaf will grow in pretty much the same conditions as Rotala macrandra, Rotala wallichii, et al. Give them moderate NO3 (5-10ppm), high PO4 (1.5-2ppm), plenty of light, and plenty of iron (Flourish/TMG). They also seem to like water on the softer side (doesn't have to be SOFT, but not the more extreme GH 12-15+).

If Rotala magenta really does not work out, a more suitable replacement would be Ludwigia arcuata (as they have similar leaf texture and color) which is much easier to grow.

Carlos

Lazaro said:

I'm interested in trying out R. Magenta, instead of R. Macrandra, because if its smallers leaves more suited for a 20 gallon.

Click to expand...

There is also Rotala macrandra "green", which is about 1/3 the size of normal R. macrandra in both the stem and leaf. It grows to about the same color as R. indica with the soft open look of R. macrandra. Look at my tank 7/17 in the aquascaping section. R macrandra green is the isolated stand to the left of center.
___
Jeff

I'll agree with proper nutrients Rotala Magenta shouldn't be too difficult. I grow it as a very red plant that turns slightly green when shaded. Beatuiful plant that can be topped over and over without any problems. It does not look much like Rotala Macranda at all, more like Rotala indica or Ludwigia arcuata.

tsunami said:

Rotala macrandra var Narrow Leaf will grow in pretty much the same conditions as Rotala macrandra, Rotala wallichii, et al. Give them moderate NO3 (5-10ppm), high PO4 (1.5-2ppm), plenty of light, and plenty of iron (Flourish/TMG). They also seem to like water on the softer side (doesn't have to be SOFT, but not the more extreme GH 12-15+).

If Rotala magenta really does not work out, a more suitable replacement would be Ludwigia arcuata (as they have similar leaf texture and color) which is much easier to grow.

Carlos

Click to expand...

My experience has been to the contrary as far as low GH goes. Until recently I had no luck growing Rotala macrandra or Rotala magenta. The new growth tips always stunt and the small new leaves are twisted. Even though my tap GH=8, I thought I might try more Ca just in case because the symptoms do look like calcium deficiency. Well, after a month of CaCl2 addition (GH to 13), my rotala macrandra is drop dead gorgeous, blood red, growing/branching like crazy. Rotala magenta is doing much better as well.

Then you have had the opposite experience. I could not grow the Rotalas in Chicago tap water (GH ~13-14) for a very long, yet could always grow them in Miami's GH 5 tap water.

A few months ago, I began to add a 50/50% tap/RO mixture at water changes which has dropped my GH down to around 7. I am now having great success with all the Rotalas I had difficulty growing before in Chitown -- macrandra "Green", Nanjenshan, pusilla, sp. Goias, and rotundifolia "Green," etc. I haven't tried Rotala macrandra (red broad) in here again (have it emersed in Miami, actually), but the layout just doesn't call for it... but I am tempted.

Perhaps Ca/Mg relationship is the culprit and not actual hardness? Hmm.

Carlos

tsunami said:

Perhaps Ca/Mg relationship is the culprit and not actual hardness? Hmm.

Carlos

Click to expand...

That's what I was thinking as well. Separate accurate measurements of Ca/Mg require expensive kits, so I am not sure what exactly the values are in my tap. I am also doing an experiment with partial RO with small Ca addition to see how it turns out for me, so it will be softer water with higher Ca/Mg ratio(actually it might be any other elements in tap water, like Ca/TDS? because some people report Ca/K also matters, but not in my case). But it is a low tech tank w/o CO2 so it would take a long time to see the effects.

If you call your water company, they'll tell you the ratio of calcium to magnesium. In my case, it's about 3 to 1.

shalu said:

That's what I was thinking as well. Separate accurate measurements of Ca/Mg require expensive kits, so I am not sure what exactly the values are in my tap.

Click to expand...

Hi shalu

Surely you already have a GH kit, so the only one you would need to add is a $6 Ca test kit. You can get Mg concentration by testing for GH and Ca, then calculating the Mg.

Water hardness, magnesium and calcium article

Edward

Edward said:

Hi shalu

Surely you already have a GH kit, so the only one you would need to add is a $6 Ca test kit. You can get Mg concentration by testing for GH and Ca, then calculating the Mg.

Water hardness, magnesium and calcium article

Edward

Click to expand...

The only problem is, my $6 Ca test kit(AP one I think) was for SALT water, and I know for sure its reading is way off for freshwater, because I did an experiment by adding NaCl into the water to mimic salt water to some degree, and Ca reading is very different. In addition, it is in increments of 20 ppm. So combined resolution of GH(1 deg) and Ca makes accurate determination almost impossible. Or can you suggest a good, cheap Ca test kit for freshwater?

Hi Shalu

Look at the article again. There is a description on a Hagen test kit. Most of us use it with great success. The increments of 10 ppm work just fine and we never had a bad kit.

Edward

That looks like it to me.

I agree with Carlos' assessment that it prefers softer water. Some Ca is required, but I've found most Rotalas, this one included, do best in GH <6

The "magenta" I've grown does get a somewhat more orange hue than the normal macrandra I've grown and seen. It's a very pretty looking plant when it's doing well.