THe PDF file didn't work for me, but hunting thru every page of their WEB site, I don't see a clear application for aquatic plants, a clear definition of what it is or what it does. On this page:
http://www.organicsa.co.za/Knowledge...Plants6-99.htm
it says it is available in two base forms, 1 is calcium carbonate, 98%, and the other is Molasses! I do not think I would want large amounts of either in my substrate. It's primary use seems to be to make the plants more disease resistant and resistant to bugs without pesticides. It also mentions larger root growth, but no where does it talk about using with aquatic plants.
Their Penac water product does mention aquariums, but it is to treat the water and somehow cut back algae, not to benefit plant growth. The same product is used as a sewage treatment. Their "plant" Penac is what contains calcium carbonate and is a soil treatment. As far as I could tell, Penac W (water) is a liquid for treating water quality. Where do you see an application for us?