Trying to raise Nitrates

[Aquattro]

Originally Posted by reefwars

You can dose potassium nitrates as well but I have no experience with that.

That was the one I read about on RC the other night.

[reefwars]

Originally Posted by Aquattro

That was the one I read about on RC the other night.

I know people dose either nitrates or phosphates to get that balance between n and p but I'm not sure if Sps has a sweet spot for nutrients I would think any two coral will react different. Now if you can't drop po4 because nitrates are two low

[Aquattro]

Originally Posted by reefwars

I know people dose either nitrates or phosphates to get that balance between n and p but I'm not sure if Sps has a sweet spot for nutrients I would think any two coral will react different. Now if you can't drop po4 because nitrates are two low

For me, I always want to see 0 for both, so I'm not sure I would add any back in. You're always going to have a bit of both in any system, but a reading of 0 on a test kit simply states that the system is absorbing it (corals, sandbed, etc)

Having undetectable levels of both, and the state of my SPS doesn't inspire me to add anything back in. If Greg isn't happy with his coral, I might be looking at other areas first.

[reefwars]

I agree but a zero reading doesn't say much especially on low grade kits. I know corals like bacteria use more nitrogen than phosphorus whether or not there's a perfect number I font think there is but they do need some as their basic needs.

I wouldn't be adding nitrates unless I am carbon dosing and even then it would have to be severe.

Not sure overfeeding will do much besides add more phosphates, upping the bioload will help but if carbon dosing then it's only temp until the denitrifying bacteria catch up.

A zero is kind of a neutral point , are we below zero or are we way below zero , I agree shooting for zero on hobbyists kits is ideal as there is sure to be n and p being used in conjunction to what's being read.

If colors are the issue or even growth then I too would look at other things mainly lighting , totm on RC right now only measures three parameters alk,salinity and phos and his phos is 0.21 so I don't think having it really low is a must as he obviously has no issues with growth colonies are huge and colors are amazing, 400w radiums baby lol

Greg what would make You think your nitrate deprived or do you think that?

[reefwars]

stole this from RC:

Originally Posted by tmz

It's certainly seems counter intuitive to dose nitrate or another nitrogen source but it may make sense.

The redfeild ratio is rather useless as a guide other than to offer perspective on the general en masse proportions of carbon(C)106:N) 16: 1 P in ocean plankton. Organisms may approximate those levels but some including some bacteria vary significantly . Even if food put in the tank is close to those proportions, the activity in the tank may not use them in those proportions. All in all, trying to use the redfield ratio to obtain a generalized optimal N to P ratio seems convoluted. Using tank levels of N and P vs natural seawater levels seems smarter and more direct.

To clarify the idea as to why dosing N might be necessary, a brief look at the three major nutrients coming in and going out of the bio available mix in the tank may be helpful

Organic carbon coming in for the most part with foods can be used for energy or sunk in refractory( non bio available) organics like humic and fulvic acids ;some may also be contributed by photosynthesis. So, the amount coming into the tank is not really the bio available amount in the tank.
In many tanks it seems there is a shortfall as N and P levels climb. If there was enough organic C, the bacteria would use up the N and P too and tank levels would approximate nsw levels ( PO4 ca .005ppm and NO3ca. 0.2ppm) more often than they do. This imbalance is the basis for organic carbon dosing( vinegar, vodka, pellets, sugar, etc)
Unfortunately, hobby level measurement of organic carbon is not possible. Even high level analyses with $ 50 K analyzers don't really tell you what organics are present and whether they are bio available. So, we use No3 and PO4 as sort of a surrogate measure for nutrients, often ignoring organic carbon.

The proportion of N in and N out varies vis a vie the proportion of P in and P out too. The bacteria , consume C,N and P for food( ie, they assimilate them) and in turn are exported primarily by skimming . Even if we assume they have a perfect 116C to16Nto1 P biomass and the food into the tank also has these exact proportions,more N will be exported than P.
Anaerobic activity where the bacteria use NO3 for oxygen when free oxygen is used up exports extra N . NO3 is reduced to N as the oxygen is taken ;some of the N which binds to other N forming N2 which bubbles out into the atmosphere. How much of this occurs is variable from tank to tank but it does deplete nitrogen in addition to the nitrogen assimilated by the bacteria as biomass;there is no other such exit for P .
This is why many use gfo or other adsorbents and or precipitants for PO4 along with organic carbon dosing.

Sometimes, N levels at 0 may induce some coral paleness, perhaps from an N deficiency for the zooxanthelae or the coral itself. Some think adding extra N via sodium nitrate or calcium nitrate will remedy that and also help the bacteria to reduce more P. Very plausible positions,imo. Some ,including me prefer to add extra N via aspartic acid and amino acid which also adds some organic carbon.

[reefwars]

a little reading as its gets complicated.

http://reefkeeping.com/issues/2006-08/cj/index.php

[Aquattro]

Originally Posted by reefwars

a little reading as its gets complicated.

That's when I stop reading. Feed fish, change water, clean skimmer. Done.

[straightrazorguy]

Pee in the sump!

But seriously, I'm nitrate limited too. I run biopellets (carbon source), I have high phosphates, and undetectable nitrates. From my reading, I take it I need to up my nitrates in order to lower my phosphates.

Sorry I don't have a solution, but I'll tag along....

[reefwars]

Originally Posted by straightrazorguy

Pee in the sump!

But seriously, I'm nitrate limited too. I run biopellets (carbon source), I have high phosphates, and undetectable nitrates. From my reading, I take it I need to up my nitrates in order to lower my phosphates.

Sorry I don't have a solution, but I'll tag along....

Like all forms of carbon dosing Your pellets remove more nitrates than phosphates so running either more amounts of gfo at a time or less amounts more often would be better than raising your nitrates. You can also remove some pellets if you think it's really low. I believe it's about 16:1 for the ratio . Again over feed will add more po4 than nitrates.

I'm currently removing the biopellets and replacing with vinegar more control and all around healthier than ethanol or sugars

[reefwars]

There's more to Colors and growth than n and p , lighting and flow are also crucial