I set up these zero tech, 1 gal planted bowls for about three years. There is no filtration, aeration or heater, just 4 to 5 hour sunlight through my west facing window in the afternoon. The intensity of sunlight is so much stronger than artificial high light that I measured 600 PAR in the sun and 70 PAR in bright shade. Even after placing a vinyl grid sunscreen, I still measured 250 PAR in the sun.
I assumed that having super high light, stem plants would turn red and grow at unmanageable rate. I was wrong. My Luwidgea, Rotala, and Mermaid weed grow at snail pace and stay green, and I seldom need to prune them. I think limited CO2 constraints their growth rate and redness. pH rose from 7.2 to 8.8 pre and post sunlight period, suggesting CO2 is depleted to less than 0.1 ppm at peak sunlight based on kH pH table. Temperature also fluctuates substantially by as much as 12 C difference seasonally and between day and night in a HVAC room.
With super high light, I was afraid of turning it into an algae farm. But it did not. After balancing out, the water is crystal clear and free of all algae except green thread algae (spirogyra and Clado) which I had to remove with a tweezer every now and then. Green thread algae thrive on the same healthy conditions as green plants and would not go away. Fortunately, green thread algae attach weakly to plants and come off easily in strands.
Since I can’t get any red from stem plants, I hang a few Coleus for color. They root quickly in water, but dont seem to grow. My cherry shrimp grow and breed, but shrimplets don’t seem to make it, so the population is not self sustaining. I don’t know why. Is it because water parameters ( temperature and pH) are not stable, or the the lack of water circulation. I do 20% water change weekly, replacing with fertilized water from my high tech tanks.
I assumed that having super high light, stem plants would turn red and grow at unmanageable rate. I was wrong. My Luwidgea, Rotala, and Mermaid weed grow at snail pace and stay green, and I seldom need to prune them. I think limited CO2 constraints their growth rate and redness. pH rose from 7.2 to 8.8 pre and post sunlight period, suggesting CO2 is depleted to less than 0.1 ppm at peak sunlight based on kH pH table. Temperature also fluctuates substantially by as much as 12 C difference seasonally and between day and night in a HVAC room.
With super high light, I was afraid of turning it into an algae farm. But it did not. After balancing out, the water is crystal clear and free of all algae except green thread algae (spirogyra and Clado) which I had to remove with a tweezer every now and then. Green thread algae thrive on the same healthy conditions as green plants and would not go away. Fortunately, green thread algae attach weakly to plants and come off easily in strands.
Since I can’t get any red from stem plants, I hang a few Coleus for color. They root quickly in water, but dont seem to grow. My cherry shrimp grow and breed, but shrimplets don’t seem to make it, so the population is not self sustaining. I don’t know why. Is it because water parameters ( temperature and pH) are not stable, or the the lack of water circulation. I do 20% water change weekly, replacing with fertilized water from my high tech tanks.