Rotala macrandra growing in the non-CO2 low-tech tank


Junior Poster
Jan 22, 2015
I did not expect to grow Rotala macrandra in a non-CO2 tank from the first beginning. My aquarium was set up 1 year ago, I dosed glutaraldehyde daily as the carbon supply, until January I used up glutaraldehyde. The tank became a real non-CO2 tank since January. I also stopped dosing nutrients from that time. To my surprise, Rotala macrandra survived and kept growing till today.

This was my tank, the pictures were taken 2 days ago.

My aquarium is a 3-foot 50 gal tank, I used OMLOPP LED from IKEA 80 cm x 2 for the aquatic plants, and another 3 mounted 25 cm above the aquarium for the land part. Two months ago I elevated the lighting for the land part from 25 cm to 31 cm, and increased the OMLOP LED 80 cm from 3 to 6 for the Phragmipedium. Rotala macradra is doing well so far after changing the lighting.

Rotala macrandra:

View attachment 248004

I use Kanuma pumice as the substrate in the aquarium. The CEC of Kanuma pumice ranges from 30-50 meq/100g, it is a good substitute for ADA aqua soil or Akadama. In addition, the color of Kanuma pumice is bright and it is cheap here (in Taiwan). The KH of my aquarium is maintaining at 1 dKH due to Kanuma pumice, while the KH of the tap water is 3.75 dKH.

I use activated carbon as the filter media. Activated carbon has an incredibly large surface area per unit volume that is beneficial for growing microorganisms, thus more CO2 productions.

I suppose that low light, lower KH due to Kanuma pumice and activated carbon that provides more surface area for microorganisms are the main factors that help Rotala macrandra grow in my non-CO2 tank.
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Article Editor
Staff member
Lifetime Member
Article Editor
Sep 16, 2015
Hillsboro, OR
That's a good looking tank. Can you provide a list of plants you have had success with.

I was also growing Macandra in my shrimp tank with glut and Flourish dosed daily. I recently switched it out for some Macandra narrow leaf and reduced my dosing to 2x per week and plants are still growing, but slow

It is actually surprising how many plants you can grow without CO2. it's not optimum growth, which is expected.

Plants I have had success with are Ludwigia Mini red, L. Aromatica, R. Rotundafolia, A. Pedicellata, P. Helferi, AR. Variegated, S. Repens, Erio Vietnam and Malayatoor, Cuphea, R. Florida (struggling), hydrocotyle tripartita, Monte Carlo, DGH Mini, Buces, Anubias.


Micros Spiller
Feb 16, 2015
Wow great looking plants! It's nice to see that its possible to grow these so-called difficult plants without co2. You obviously have a good balance of everything.

The Proserpinaca palustris looks very nice too.

Tom Barr

Staff member
Jan 23, 2005
I have Ammannian pedicillata growing in my non CO2 tank. Smaller, but nice.