No3, No4

[justy]

I would like to ask a question.
I'm pretty sure that there is no one answer as there seldom is in this hobby. I have been keeping reef tanks for over twenty five years, and it still amazes me that people manage to have great success with different parameters. The ones I'm interested in is NO3 and PO4.
If people with very colourful and healthy tanks could chime in with their levels maybe we can find some common ground.
How often do we see some tanks with No3 of 0.2 and PO4 of 0.4 also some tanks with 0 of each.
Plus some tanks work with No3 of 5 and PO4 of 0.1
What is going on there must be some logic to all the different parameter levels.
Anybody got any insight as I'm not sure we're to set my levels at to achieve the best results.
Many thanks justin :thumbsup:

 

[Nano sapiens]

NO3: A reef aquarium can have nitrate readings that are just below the threshold of the test kit and this can be sufficient for the organisms. Also, if the tank has a continuous supply of low level ammonia (from a good fish population, for example), this resource can be utilized as well. If you look at reef systems where NO3 is undetectable, but fish populations are relatively high (and/or the corals are fed regularly), you'll typically notice colorful corals.

PO4: Test kits can only read PO4 inorganic phosphate (aka: orthophosphate), so organic phosphate is an unknown for the typical reef tank. As a result, a tank can have 'undetectable' PO4, but combined with the organic phosphate in the system, this can be enough to keep coral colorful, healthy and growing.

Basically, if a tank has sufficient organic nutrients, the inorganic can be kept quite low. Conversely, if inorganic nutrients are somewhat elevated then less organic nutrients would be needed. It has been suggested that corals prefer to use organic nutrients and this is what they would primarily consume in the wild on a pristine oceanic reef where inorganic nutrients are extremely low. When both inorganics AND organics are below a certain theshold, life's processes can't proceed optimally.

 

[justy]

Thanks for the very detailed answer.
So if we see people struggling to keep acropora with very light colours, we can assume that they either don't feed enough do not have enough fish or have stripped their water of nutrients with aggressive use of pellets or phosphate removing media.
Is it that the more successful reef tanks adopt more natural methods of nutrient export and multiple techniques ie. DSB, cheato, carbon and bacteria dosing and of course a good skimmer?
Thanks again for a very clear answer
Justin.

 

[Tigerdragon]

Most went with a tank stripped of nutrients thinking was this is the best way to control and prevent algae breakouts. Recent studies have been finding that the stripped tank is actually starving the corals. Most like no3 of .03-.05 and po4 around 5-10. These levels you can still control algae with a proper cuc, filtration, and husbuandry methods. This way you dont starve your coral. There also have been very succesful tanks that had a po4 of 1.2 and higher but are what they call iron limited meaning little to iron and have no algae problems. In the end slightly elevated levels other than ammonia and nitrites will not kill or hurt your tank as you only have to look to nsw and see that it has these present

 

[Nano sapiens]

Thanks for the very detailed answer.
So if we see people struggling to keep acropora with very light colours, we can assume that they either don't feed enough do not have enough fish or have stripped their water of nutrients with aggressive use of pellets or phosphate removing media.
Is it that the more successful reef tanks adopt more natural methods of nutrient export and multiple techniques ie. DSB, cheato, carbon and bacteria dosing and of course a good skimmer?
Thanks again for a very clear answer
Justin.

Since the typical end goal is to maintain relatively low inorganic nutrients and have sufficient organic nutrients present for the organisms, the methods used are more a preference of the aquarist. IMO, a combination of filtering methods is not necessarily 'better' than having just one or two. What's important is whether the method(s) chosen result in system stability and provide an environment that meets the organisms' requirements.

For example, I use water changes and the regular removal of detritus (sand bed vacuuming, etc.) as the sole means of maintaining a 7-1/2 year old mixed reef nano tank. I consistently have NO3 less than 0.5ppm (Elos) and PO4 'undetectable' (Salifert)...and very little algae. Since I feed the tank daily, there is a continuous influx of organics into the system which results in nicely colored corals of all types and moderate growth. I can achieve faster growth by simply feeding more/more often, but then I would also have to step up my maintenance routine to cope with the added inorganic nutrient buildup or else I'd end up with increasing eutrophic conditions (more algae, bacterial blooms, cyanobacteria, excessive sponge growth, etc.).

 

[Nano sapiens]

Most like no3 of .03-.05 and po4 around 5-10.

I believe you have NO3 and PO4 flipped around.

 

[justy]

Yes all makes sense.
I am currently bringing No3 down slowly from 4 ppm to 0.75 currently, this has taken about 2 months using siporax and aquaforest bugs and carbon source/food. PO4 has stayed at 0.08 would like to bring it down to 0.04 if possible.
I'm hopeful that this will colour my corals even more. I'm increasing food input and using AA sparingly.
Thanks again for your input,nice to hear what other reefers are doing.
Justin

 

[Nano sapiens]

Yes all makes sense.
I am currently bringing No3 down slowly from 4 ppm to 0.75 currently, this has taken about 2 months using siporax and aquaforest bugs and carbon source/food. PO4 has stayed at 0.08 would like to bring it down to 0.04 if possible.
I'm hopeful that this will colour my corals even more. I'm increasing food input and using AA sparingly.
Thanks again for your input,nice to hear what other reefers are doing.
Justin

One of many ways to address an inorganic buildup. Happy reefing