Nitrates to low

Sean minor · Oct 27, 2014

What happens if the Nitrates in your tank hit 0? Had aquariums for years and years. Nitrates in my FO tank stayed between 20 & 80, reef 5 &10.
Tank in question is a 180 mixed reef holding a bunch of large fish and corals. Couldn't keep the Nitrates below 30 and keep the fish happy so I added a large Bio Pellet Reactor. It works great but it has no flow control it pulled all measurable Nitrates from the system. My thought was to do nothing and let the pellet level drop and see what happens. I was wondering will no nitrates affect anything other than so of my soft corals witch don't seem very happy, LPS and SPS seem ok

Randy Holmes-Farley · Oct 27, 2014

If you strip nutrients too low, organisms can suffer. Corals become pale (even SPS), for example, and many soft corals won't thrive.

That can be helped by dosing more foods or things like amino acids, but not overdoing nutrient export has become important as the tools have become available to drop them too low.

Sean minor · Oct 27, 2014

Well I definitely over did it. I did up my feeding just a bit. Need a way to fail back the Bio Pellet Reactor. With any luck they will come back up a touch. Funny you try for years to keep the nitrates low then you wip them out

Randy Holmes-Farley · Oct 27, 2014

That's one reason I prefer to dose liquid organics (such as vinegar): it is easier to rapidly adjust the dose as needed.

JOKER · Oct 27, 2014

I had issue with pellets as well. Nitrates were high but phosphate was low. When I got to full amount of pellets my nitrates dropped and phosphate started to climb, then I had phosphate to deal with. I think around 14-1 ratio or something around that. Everyone I know that runs pellets feed LOTS! I have also went back to dosing but I use vodka 40 proof much easier to control for me.

Sean minor · Oct 27, 2014

I was doing the vodka thing too, just thought the pellets looked like a good idea. I use GFO to keep the phosphates down. I just need to monitor the nitrates closely and be able to cut the flow to the tank back ( the right amount ). I guess I missed it. Started feeding a little heavy till I see something. Sure makes the Angels happy.
Thanks for everyone's help

marke · Oct 27, 2014

What is nitrate level of NSW? Do we target this number? How do corals get amino in the ocean?

Randy Holmes-Farley · Oct 28, 2014

marke said:
What is nitrate level of NSW? Do we target this number? How do corals get amino in the ocean?

Corals mostly get amino acids from their zoox, but also some from foods. Certain ones (such as glutamic and aspartic acids, may be especially useful and in short supply.

here's a blurb on nitrate:

Nitrate in the Ocean

Nitrogen takes many forms in the ocean, one of which is nitrate. Other forms include dinitrogen (N₂), ammonia (NH₃/NH₄⁺), nitrite (NO₂^-), and a myriad of nitrogen-containing organic compounds. Of the inorganic species, nitrate is often, but not always the highest in concentration. Concentrations in the ocean vary considerably from location to location, and also with depth.2 Surface waters are much lower in concentration due to scavenging by various organisms, and are often less than 0.1 ppm nitrate (not that all concentrations in this article are in ppm nitrate ion, and not in ppm nitrate nitrogen). Deeper waters typically range from 0.5 to 2.5 ppm nitrate. Surface regions where upwelling of deeper water takes place will also have these higher values.

Most of the nitrate present in the ocean results from the recycling of organic materials. The degradation of plankton, for example, provides nitrate:
(CH₂O)₁₀₆(NH₃)₁₆(H₃PO₄) + 138 O₂ → 106 CO₂ + 122 H₂O + 19 H⁺ + PO₄^3- + 16 NO₃^-
plankton + oxygen → carbon dioxide + water + hydrogen ion + phosphate + nitrate

Other sources of nitrogen to the ocean are volcanic emissions (mostly as ammonia), fixing of N₂ by blue-green algae, and run off from land. All of these become part of the nitrogen cycle, and a portion will end up as nitrate.