Join Date: Oct 2010
Location: Victoria, Australia
Using IAL tints the water, which means not as much light will be available to your plants. You can compensate by using a higher rated light, or instead choosing lower light plants such as anubias, java fern etc.
Also it depends on how dark your water to be. I was successfully growing ambulia in a very dark tank (think water was almost black) by using a very strong light over the top.
I have found many aquatic plants prefer slightly softer water. You just don't want to make it too acidic, although some of my tanks have very low pH and carbonate hardness, and all my 'low tech' plants are thriving.
Betta splendens don't really need a blackwater environment. They aren't like some of the wild bettas that require an extremely low pH to thrive. I only use a very small amount of IAL in with my CTs because of their finnage. Otherwise none of my other bettas used to have any in with them.