I read in your article that ponds that use conventional filtration systems produce lots of nitrates, but in my pond after testing, it shows very little nitrates (15-ppm) can you explain that to me? I do several water changes and this keeps my nitrates low. With the Anoxic Filtration System are water changes necessary, to keep nitrates low?

Q:

I read in your article that ponds that use conventional filtration systems produce lots of nitrates, but in my pond after testing, it shows very little nitrates (15-ppm) can you explain that to me? I do several water changes and this keeps my nitrates low. With the Anoxic Filtration System are water changes necessary, to keep nitrates low?

A:

When hobbyists say nitrates are low which nitrate compound are you reading on your test kit? Most, if not all nitrate test kits (this includes LaMotte test kits) record nitrate nitrogen (NO3-N). If your test kit only reads nitrate nitrogen, then your numbers will always be lower than a test kit that test for nitrates (NO3). If your test kit only reads, nitrate nitrogen then you must multiply the number you get by 4.4. This means in actuality, your pond has 66-ppm of nitrates, which is extremely high. You must also take into account that if you have any nitrites this can cause serious interference with most if not all nitrate test kits and should be determined and compensated for if present. 

 Now let us take for example the Anoxic Filtration System. In the 27 years that I have been experimenting and studying and researching this system, I only clean the filter system out twice a year, once in March and another time in late autumn at the end of October. That was the only water changing my pond has ever received in 18 years during that test period.  

I personally test for nitrates using only the most preeminent titrating test kits available on a continuous basis every month. In all the years of using titration testing for (NO3) nitrates, my levels have never been over 13.06-ppm (NO3-N = < 3.0ppm) 1, and most of the time, it is considerably less. (More in the range of 2-ppm to 10-ppm.) That is excellent for an 18-yearold pond, which has never had a complete water change; this is extremely low (the fact is many saltwater hobbyists would like to have their Nitrates levels this low). We can then conclude that this system is doing the job that it was designed to do, of eliminating nitrates as an end byproduct. We can also conclude that the heavy fish loads; of one Koi per 50-gallons (189.2 Liters) of pond water, has very little effect on the capability of the Anoxic Filtration System reduction capabilities.

The fact is, one hobbyist in Australia, doing nothing different (as for as pond husbandry) from previous years, notice a huge 65% reduction in Nitrates by adding only Nine Biocenosis Clarification Baskets after his main filtration system. At years-end, his Nitrates are always around 100-ppm, but using the Biocenosis baskets brought the year-end Nitrates to only 35-ppm.  

1: Date this titration reading was taken / August 27, 2004, / TIME: 12:50 p.m. / Biomass = > Heavy / Temperature: 84°F. (29°C) All other parameters > 0.0000 ppm. / < 0.0011ppm. / pH 7.4/ NO2 & NO3 > 0.0015ppm /DOC#17254.4