HIGH NITRATES

[AbbeysDad]

Many, many years ago with failing fish in Abbey's 10g tank I came to realize that I had high nitrates...really high nitrates. Old school, this was before I did any testing. Now it began, I thought, because of an undergravel filter that didn't get vacuumed anywhere near enough. Along with insufficient volume/frequency of partial water changes, I thought this was the problem. But even after those were seemingly resolved, I still had high nitrates! I finally tested my well water and was amazed at how high (off the chart) the nitrates were! You see, I live in 'the country' in Central New York state and there's a 95 acre farmers field across the road. A field that no doubt gets ample amounts of manure and chemical fertilizer. Now normally when you step up tank housekeeping AND do sufficient partial fresh water changes, nitrates get under control...but not if your source water has high nitrates. After a fair amount of research, I came to learn that nitrates in source water, especially in agricultural areas has become quite common. Modern agriculture often uses a fair amount of fertilizer that ends up in the water!
So began my serious study of the nitrogen cycle and My Nitrate Fight. This all led me to discover resins that adsorb ammonia and nitrates from water and a pre-filter that I use to this day. I also explored all the ways possible to Lowering Aquarium Nitrates. All of this also led me to experiment with Dr. Kevin Novak's Anoxic Biocenosis Clarification Baskets as denitrate filters (where I have two in a 45g sump on my 110g stock tank.
For a deep dive check out Aquarium Water Quality.
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Footnote: I could be wrong so don't quote me, but I have the feeling that nitrates in source water as the result of fertilizers are potentially or somewhat less dangerous than tank generated nitrates. The decomposition of organic waste in the tank results in nitrates to be sure, but also other pollutants that create compounding negatives...but again, this is my impression with no scientific data to support it ~ so grain of salt here.

 

[Uberhoust]

I agree about the nitrates from water sources but if your nitrates are really high I would start to wonder how fast the water from the fields is getting to your well, or whether you are getting some surface contamination. I am also curious what your thoughts are on the effectiveness of the Anoxic Biocenosis the linked article mentions issues with the cat litter but doesn't quite describe how well the Safe T Sorb worked. I read these while working so I may have missed something. I wonder if activated charcoal would absorb nitrates if it was new enough.

 

[AbbeysDad]

I would start to wonder how fast the water from the fields is getting to your well, or whether you are getting some surface contamination.

My drilled well is 110 feet deep with 40 feet of casing. As I mentioned, the field across the road is 95 acres. They grow hay now and since they've switched from chemical to manure as fertilizer I believe that my nitrates have decreased. (However, I have read that nitrates in ground water, especially in agricultural areas is an ever increasing problem.)

I am also curious what your thoughts are on the effectiveness of the Anoxic Biocenosis the linked article mentions

I just switched to the SafeTSorb clay this spring so I believe that it's too soon to tell. However, I have doubts that it is a cure all for nitrates and for now, I continue to do ample water changes, often with pre-filtered water.

I wonder if activated charcoal would absorb nitrates if it was new enough.

Although activated carbon aDsorbs many impurities, I do not believe that it will remove ammonia and nitrates like API Nitra-Zorb does. Nitra-Zorb is specialized resin that has an affinity to collect nitrogenous compounds. The real beauty is that it can be recharged with ordinary salt water - I have used the same resin in my DIY filter for thousands of gallons and it's still going strong!

 

[Zoeeannee]

I know it won’t fix the source of your nitrate problems, however I have used “Seachem De Nitrate” added to my external filter for my 300L and also “API Nitra-Zorb Pouch” in my 65L (not added to the filter as it wouldn’t fit but just added to the tank and it worked) and they have massively reduced my nitrates which were sky high. I expect you probably have solutions in place whilst finding and hopefully fixing the source, but thought I would mention just in case

 

[StevenF]

Footnote: I could be wrong so don't quote me, but I have the feeling that nitrates in source water as the result of fertilizers are potentially or somewhat less dangerous than tank generated nitrates.

nitrogen is often pressent in organics as N, NO, N2H2, and NH. When the organics start to break down some of the nitrogen is released as Ammonia or nitrite or as N. Now bacteria will work on those and eventually you get nitrate. So if you start with nitrogen containing organics you can get a wide variety of Nitrogen some of which are much more toxic than nitrate.

For synthetic fertilizer there the most common used on farms is ammonia nitrate, ammonia water solution, and potassium nitrate.The first two have ammonia which can be very dangerous to fish Potassium nitrate unlike all the others doesn't break down like organics do so it stays around longer. So overall it mostly a wash with each being as bad as the other.

 

[AbbeysDad]

I have used “Seachem De Nitrate” added to my external filter for my 300L and also “API Nitra-Zorb Pouch” in my 65L (not added to the filter as it wouldn’t fit but just added to the tank and it worked) and they have massively reduced my nitrates which were sky high.

Seachem Matrix and De*Nitrate are just pumice stone (a type of lava rock) with large claims about micro pores supporting anaerobic bacteria that will convert nitrates into nitrogen gas. As I indicated in my article, I experimented with a mix of Matrix/De*Nitrate for a long time but never saw any positive results. As I also mentioned in my article(s), I continue to use API Nitra-Zorb to this day in a repurposed API Tap Water Filter to remove nitrates from my source (well) water.