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Nitrate Dosing


Thank you for all the inputs landshark. Much appreciated. I have tried LaCl in the past with a 5 micron filter sock but due to poor placement i flooded 10-20 gallon. I am a forgetful person πŸ™‚ and want something that is more tolerant of that. I am going to set up the Reactor that Jason described.

I have not paid attention to phosphate and lost (i believe) two coral colonies to it. (not expensive but decent size grown from a frag). (i think the trigger was my sudden lowering of alkalinity by stopping the dosing as it was much higher than recommended range but is suggested to be protective against high phosphate by prevent phosphate crystallization in the growing coral skeleton which is the main phosphate toxicity to coral in addition to growth of unwanted algae). I assumed my methods will also take care of phosphates in addition to nitrates but now have learned that phosphate is harder to take out then anything else.

So here is quick summary for people who are wondering what the hell am i talking about.

Aquarium is a closed ecosystem. As long as you don't add anything to the tank it is just a bucket of water.

Once you feed (even the simplest of food like phytoplankton or brine shrimp eggs) you are adding nutrients in the water with mainly Carbon, Nitrogen and phosphates and many other inorganic and organic micro elements.

All these nutrients will be utilized by what you have in the tank for metabolism to stay alive and grow. End results of all the process is left over carbon, nitrogen as nitrates and phosphates and micro elements. If they are not readily used then excess would be available to any opportunistic organism such as algae (red, green, brown, black you name it). Which is never eradicated but only suppressed or contained to an invisible level.

There is no known way of putting in just enough so that there is nothing left over.

What is left over needs to be removed mechanically: removing debris, detritus by filteration, siphoning, vacuuming, etc. But the best and most efficient method would still leave Dissolved material.

a. Organic Carbon: readily used and most effectively by the bacteria and is always a limiting factor for bacteria and algae. No known harm or problem with quantity as never known to be a problem (except sudden dosing with dissolved organic carbon can cause bacterial bloom, which may not be damaging except by depleting oxygen). Excess carbon is dosed to prevent this becoming a limiting factor for removal of everything else below.

b. Nitrogen mostly in form of nitrate: This is the first challenge in aquarium keeping as nitrates are toxic and excess of nitrates can occur in poorly working aquarium and is the most common problems. It can be removed by:
i. Skimming to remove dissolved proteins which are source of carbon, nitrogen and phosphates.
ii. carbon dosing to promote bacterial growth to keep using nitrates. in the end these bacterias need to be removed which is usually achieved by skimming. skimmer scum is likely the richest bacterial place in the whole aquarium. alternate would be siphoning debris which harbors bacteria from sand or bare bottom.
iii. Growing (macro) algae which is contained and easily harvestable.
iv. Growing bacterias that convert nitrates to free nitrogen which is dissolved in aquarium water and then evaporates as free air when water fully saturated (which it mostly is). This is achieved by creating oxygen depleted nutrient rich zones (most commonly through Deep Sand Bed).
v. Growing plants or corals that grow fast and can be removed later on such as mangroves and xenia.
vi. Advance denitrators. not commonly used.

c. Phosphates: I will write on this next.

( I did not proof read, sorry for errors).

c. Phosphates: The source of the phosphates is mainly the food, a food by food analysis of food content of phosphates is available on internet with searching but the difference between foods was minimal. Washing frozen food decrease the phosphate by 1% (i.e. is 1% of 0.1 % that food contains) which i think is not worth it. and much more is added by using flakes and other foods. Other less common sources are phosphates could be use rocks and used sand that has absorbed phosphates. Majority of phosphate in aquarium is present as organic or bound inorganic phosphate and is not measure with routine testing which only looks at free inorganic phosphate but is a marker of total phosphate content. Ideal level is likely below 0.1 ppm but i am not very sure on how to answer this well. lets say my target would be definitely below 0.1 but closer to 0.03 ppm or less.

Initially i thought since it is entering in a ratio to nitrogen and carbon in food, it would also be removed in the same ratio and so if you keep nitrates low, phosphates should also be automatically low but is not the case. (esp when DSB is removing free nitrogen gas i guess, but even aquarium without DSB and only dependent on skimming and macro algae will slowly accumulate phosphate over time). So an additional method of phosphate only removal is needed and here are three options.

a. GFO or similar binding resin.
b. complexing with Lanthanum Chloride into precipitates that would eventually be filtered out or settle down.
c. Growing more algae and bacteria by removing limitation of carbon and nitrogen by providing phosphate free sources of these two. For carbon it would be Carbon dosing (vodka, vinegar or biopellets) and for nitrogen it would be nitrate in some form (Calcium nitrate or sodium, potassium or similar nitrate). This is extremely common component (and back bone) of plant fertilizers (and main component in planted tank supplements).

d. Micronutrients: No specific removal is needed for any other in particular although they do accumulate over time if not removed such as Bismuth, silica etc. Most of these are easily removed by skimming or growing xenia or growing cheatos. One other method is by doing water changes (taking out water with higher Bismuth or iron lets say and replacing with water with lower amount). That is additives in general are not needed or (even avoided) (except for Iron and iodine in some cases, esp heavily macro algae growing tanks).

In summary nitrate dosing is used along with carbon dosing to remove excess phosphate by growing more bacteria that gets skimmed out.

But nothing is as easy as it sounds. Nitrate dosing is likely one of the most dangerous method of phosphate removal and probably should not even be attempted in small volume of water such as less than 75-90 gallon.

Wow, that's a lot of information, thanks for taking the time to write and share this! I'm definitely going to need to read through this another time or two to grasp it better, but needles to say I'm glad I don't run a monster system like you and Landshark πŸ˜‰ There are definitely big problems that go along with big tanks, with not small solutions...

As Jason has said, water params may be more stable, but issues are BIG issues

[quote="Boggers-Mike" post=30893]As Jason has said, water params may be more stable, but issues are BIG issues[/quote]

Actually, I would disagree to this extent. Yes the issues can be more complex to get under control, but once there, the care for me over the last 18 months has been no more difficult than any of the other tanks I have had. I would say the biggest issue is in a larger system, it just takes more of whatever you are using to cure a problem and a longer cycle to do so, mainly because of the volume of water that is treated.

For the most part, my nightly 30 minutes time spent doing what I need to do in my daily routine has become pretty mindless. I can do what I need to do without really thinking about it.

[quote="Landshark" post=30895][quote="Boggers-Mike" post=30893]As Jason has said, water params may be more stable, but issues are BIG issues[/quote]

. I would say the biggest issue is in a larger system, it just takes more of whatever you are using to cure a problem and a longer cycle to do so, mainly because of the volume of water that is treated. .[/quote]

That's basically what I mean. When I say problems in small tanks are small problems, and problems in big tanks are big problems, I'm just referring to things like parasite outbreaks, disease treatment, taking over a tank with bad algae, etc. Much easier to correct on small tanks.

Haven't seen anyone local that has such understanding about reef aquarium. Thanks Danish.

[quote="chino" post=30938]Haven't seen anyone local that has such understanding about reef aquarium. Thanks Danish.[/quote]

There are people that i look up to. Jason would be top of the list (Jdiefenbaugh). He is the only one i know personally who has handled more than 100,000 gallons worth of experience. Many national aquarium gurus are actually not that hard to approach and many are active participants on forums such as Randy holmes (who basically taught everyone about aquarium chemistry which is evidence based).

I know!! Many people in town are very saltwater smart. But your posts cover everything pretty well. I Just came back in the hobby, reading quality posts like this save me a bunch of time on researching. So many thing I could do to keep my nutrients in check.


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