High Nitrates

There have been a few recent posts worrying about "high nitrates," wondering
how they came about.  Perhaps this will help.  Nitrate readings don't
necessarily mean you are doing something wrong.  It is just that the Laws of
Physics are not always cooperative. 

(1) Any fertilizer that lists Nitrogen WILL add Nitrates to the water. That
is how the Nitrogen exists in fertilizers!  (e.g. Ammonium Nitrate is a good
fertilizer, even though most folks nowadays associate it with explosions.) 

(2) Say your fish load in a tank emits only 5 ppm of nitrates a day. (a
rather small amount - fish are responsible for almost all of the Ammonia,
Nitrite, and Nitrate in Coral Reef environments.  Fish give off a LOT of
waste materials which your filters busily convert to Nitrates.) 

5 ppm per day amounts to 150 ppm in a month, 300 ppm in two months.  Don't be
surprised to find relatively high Nitrate levels accumulating in rather short
times!!  Unless something in your tank can use the stuff, it just accumulates
until the next water change. (One local wag says, "Eliminate it or flush it.
 Either your plants use it, or you change the water.")

I find it curious that aquatic plants, except for Water Lilies, Lotus, etc.,
seem to grow a lot better in our tanks when the Nitrate levels are very very
LOW.  Just the opposite of Corn!! No, I do NOT know why!  (  :-)  )