You can see the difference in growth after adding CO2 and the extra watt/gallon for 1 week

WEEK 5 Date: 2/5/06
pH: 6.9 (morning)
Temp:
KH: 4 (5 after dose)
GH:
NH4:
NO2:
NO3: 0-5 (before dose)
PO4: 0.15 (before dose)
Iron:
Dosing: 10 mL Flourish, 50 mL OLD Flourish, 50 mL KNO3 (10 ppm NO3), 35 mL KH2PO4 (1.05 ppm PO4)

Notes:
pH is still 6.9, so it seems to have stabilized. I upped the CO2 bubble rate to 1 bubble/sec to try to get it to 6.8

The KH had dropped to 4, so I added 1 tsp baking soda to up the KH. The nitrate and phosphate levels keep dropping to near zero, so I’m going to up the dosage to see if it will suck down even more.

The bottom leaves of the Rotala rotundifolia are still yellowing, dying. It might be because the nitrate levels are too low?