Re: Nutrient Ratios
In my experience, aquatic plants have a natural, intrinsic maximal growth
rate. This intrinsic growth rate changes over time, even under constant,
rigorously controlled conditions. The change occurs diurnally of course
and also cyclically over longer time periods. When you supply nutrients
to your plants the goal is to support this intrinsic growth rate, not to
supply nutrients at some optimal ratio to one another. Aquatic plants
have a great capacity to absorb and store mineral nutrients so as long as
they are supplied in excess, the ratio of one nutrient to another is not
critical (in terms of mineral nutrition). The rate of supply is the
critical factor and will, of course, be different for each situation.
Many studies exist in which a single nutrient was supplied at different
rates and the resultant growth and tissue content was measured. For
aquatic plants these types of experiments were popular in the 30's and
40's, though I have spent about 4 years or research doing similar work
... I think Paul K. has also spent some time on these types of experiments.