Hi Joe!
Pale growth show up if the plants don't get enough Iron or Magnesium. Since the Onyx contains and releases quite a bit of Magnesium you most likely will have to fertilize carefully your plants with some Iron.
A product called "Fluorish Iron" should be easy to find in almost any pet store.
Most likely when you added CO2 the plants started to 'eat' nutrients very fast and ran out of Iron. Keep in mind that plants can run out of other nutrients too - Nitrate, Phosphorus, Potassium, Calcium, Magnesium. With CO2 you must make sure you fertilize very carefully on a regular basis. If you have questions about that please ask.
--Nikolay
Pale growth show up if the plants don't get enough Iron or Magnesium. Since the Onyx contains and releases quite a bit of Magnesium you most likely will have to fertilize carefully your plants with some Iron.
A product called "Fluorish Iron" should be easy to find in almost any pet store.
Most likely when you added CO2 the plants started to 'eat' nutrients very fast and ran out of Iron. Keep in mind that plants can run out of other nutrients too - Nitrate, Phosphorus, Potassium, Calcium, Magnesium. With CO2 you must make sure you fertilize very carefully on a regular basis. If you have questions about that please ask.
--Nikolay
