The beautiful red stems I picked up at the last meeting have melted away on me. Or my corys unplanted them.
I think there is one or two stems left.
I am guessing 48 watts of light on a 20 gallon tank is not bright enough for them. The green plants are still growing fine, mostly java ferns, anubias, bacopa C., Hygrophilia polysperma and a some smallish crypts, nothing really demanding. My T5s are over a year old now.
Do I need may 3 or preferably 4 wpg to grow red plants?
Dearly Departed Rotala Macrandra
I'm hoping to try R. macrandra soon so I've been reading about it. I've had some nice successes in my first effort at a planted tank so I'm not too intimidated by those that say this one's tough to grow. But we'll see.... sorry you didn't have the best results.
They say grow lights aren't much less effective after a year. Time for some new ones maybe.
What are the dimensions of that 20 gallon tank? Is it high or long? From what I've been reading your lights should be plenty, however, there's probably a great difference between 2.4WPG in a high or low/long tank. I have about 4-5WPG in my main tank and everyone says that's too much! I'm probably perenially teetering on the edge of algae breakout. And the red is not entirely a product of the strength of light. Everyone's been telling me the red's come from high rate of growth (at least with ludwigia repens). My newbie guess is that your issue is a nutrients issue.
Now here's the kinda odd thing I've been reading that makes this plant "difficult." It seems this plant likes a different ration of N to P than the way people usually keep their tanks. The way I understand it, if you keep growth limited by P then your plants outcompete algae and grow well. Rotala macrandra seems to turn supa-red when its growth is limited by N. Most of this I learned from The Krib. Here's the URL: http://www.thekrib.com/Plants/Plants/Rotala.html
They say grow lights aren't much less effective after a year. Time for some new ones maybe.
What are the dimensions of that 20 gallon tank? Is it high or long? From what I've been reading your lights should be plenty, however, there's probably a great difference between 2.4WPG in a high or low/long tank. I have about 4-5WPG in my main tank and everyone says that's too much! I'm probably perenially teetering on the edge of algae breakout. And the red is not entirely a product of the strength of light. Everyone's been telling me the red's come from high rate of growth (at least with ludwigia repens). My newbie guess is that your issue is a nutrients issue.
Now here's the kinda odd thing I've been reading that makes this plant "difficult." It seems this plant likes a different ration of N to P than the way people usually keep their tanks. The way I understand it, if you keep growth limited by P then your plants outcompete algae and grow well. Rotala macrandra seems to turn supa-red when its growth is limited by N. Most of this I learned from The Krib. Here's the URL: http://www.thekrib.com/Plants/Plants/Rotala.html
Dan Please, spay/neuter your Platys.
