Nitrate’s high and stuff are dying.

Quote: Originally posted by Mark Peterson on 19 March 2003

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It is my understanding that soon after fish waste hits the water it chemically converts to ammonia/ammonium. In the presense of oxygen, billions of bacteria in the water and on surfaces like glass and rock exposed to oxygenated water consume the ammonia/ammonium as food, converting it to nitrate. Here are chemical equations for:

NITRIFICATION (Ammonia & Nitrite to Nitrate) (???)

NH₄⁺ + 2O₂ ® NO₃ + H₂O +2H⁺

DENITRIFICATION: (Nitrate to gas & water)

5C₆H₁₂O₆ + 24NO₃^- + 24H⁺ ® 30CO₂ + 12N₂ + 42H₂O

This info is courtesy of CaribSea. They published an extensive reference sheet years ago that I have recently converted to an electronic file in MS Word format. It is very informative about a number of topics. If interested, email your request and I will reply with the draft copy.

You may notice that contrary to being a reverse process as was suggested in one of the posts above, bacteria in a low oxygen environment consume sugar and nitrate to obtain energy and the waste is carbon dioxide, nitrogen and water.

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The reason why I prefer to use a protein skimmer is to remove the organics before they have a chance to decompose to NH3/NH4+.

I should be more careful how I explain things (in regards to the reaction being reversed).  I come from a chemistry (engineering) background and yes the nitrogen cycle (as far as the nitrogen molecule is concerned) is going back and forth in an oxydation/reduction reaction.

Ammonia --> Nitrate (oxydation)

Nitrate --> Nitrogen/Ammonia (reduction)

The same "type" of reactions also take place in an aquarium with regard to sulfur.

Decaying biomatter --> H2S --> S04 (oxydation)

S04 --> H2S (reduction)

Rick Greenfield, owner of CaribSea and a Ph.D Scientist of some sort himself, always used to talk of the acidic condition within the substrate which contributed to the dissolving of his product.  This process is what made using his product so beneficial because it released calcium and the other minerals from the aragonite into the water for use as buffer and coral builing material. Nobody could refute his claim because we didn't know enough about it ourselves! He claimed that eventually a person would have to add more substrate to replace that which dissolved.

Jon, Why would decaying algae create an ammonia spike? I always thought of it as leading to an increase of organic material bonded to phosphate, carbon and perhaps nitrates too. I'm in the dark here. Help!

I assumed Rick was speaking of a long term process that no hobbyist would ever notice.

Amino Acids? I would like to know how it all works and fits together so that we can be sure we are making use of the best filtration methods or to come up with better.

I agree that a skimmer takes out the organics before bacteria can get to them. SPS coral does best with good skimming. So what does that say about the use of biological filtration without skimming and its effect on SPS?

Jkelson and mrkelson- I actually didn't suggest that you add more bio wheels.  I think the ones you have are plenty and mabe too much according to jfinches point in regards to bio wheels accumulating nitrates. 

The message I was trying to relay is that the use of power heads as a means of water circulation in your tank would be a good idea.  I suggested this because you had asked if the filter with the bio wheels would create enough water movement.