Rotala Sp. 'colorata' Twised Again

Hello everyone, I am from bad English coming to Taiwan.
I used google to complete the next conversation.

After a period of effort
My ROTALA still appears twised
I did a lot of experiments and it lasted for a while.
But still failed

Normal and abnormal are planted in the same block
When new top leaves appear, twised immediately after a few days

My tap water owns GH<1 ,KH<1 ,TDS=40-50ppm ,NO3 and PO4 are <1ppm
I guess the reason may be lack of CO2, light or deficiency nutrition .
I tried to change many conditions independently.

1. Use CO2 to reduce about 1pH(pH=7.1 to pH=5.9 ) ,start and close simultaneously with the light .Although it didn't work, I still do it until the end of the experiment.

2. I started using EI, providing a total of N: P:K=10:1:10ppm of the main nutrient ,Seachem Trace 1.5cc and ADA ECA 6 drops secondary nutrition every week .Although it didn't work, I still do it until the end of the experiment.

3. I suspect that there is really calcium deficiency. After changing the water every week, I used HAGEN to make TDS up to 120ppm. Although it didn't work, I still do it until the end of the experiment.

4. After my light increased, the total number of plants improved. Finally, I suspect that the quality of the light is not correct, so I need more light than the original. I plan to buy a seneye reef spectrometer to measure the intensity and quality of light.

If the inference is correct, I will replace the light
But if there is an error, I have no other way.

This is an abnormal part of the same block


This is the same block, but the normal part, I believe that in a few days, there will still be twised