nitrate creep.. you guys should read this
- Thread starter m8r8j
- Start date
OK, I actually posted on some other forums about this very issue (nitrate creep). I even made a simple excel file that showed the gradual increase with variables being daily nitrate production, frequency of WC and size of WCs. Additional variables would be denitrification rate and nitrate level in tap water if these apply. I am by now means a maths guy, but I understand enough of the simple principles to discuss this.
As the largest WC you can do is roughly 80% whilst still keeping fish in the tank, it's not hard to see that over time nitrates will creep up. Creep won't magically stop at 100 ppm (0.01%). It will keep increasing. Of course your fish might be dead by then.
To tackle nitrate creep just do an extra water change in the middle of your normal interval once in a while. Alternatively you could do almost 100% WCs by filling the tank whilst draining it at the same time. Or you could do continuous drip if you have the right room setup for it.
The best way is denitrification, but unfortunately many of the fish we keep here on MFK aren't suitable for the easiest way - plants. I'll post my understanding of this next (copied from my post on another site).
Nitrate is a solute that dissolves throughout the water. Essentially, assuming there is no denitrification and 0 nitrates in the incoming water, every WC % reduces nitrates by the same %.
As the largest WC you can do is roughly 80% whilst still keeping fish in the tank, it's not hard to see that over time nitrates will creep up. Creep won't magically stop at 100 ppm (0.01%). It will keep increasing. Of course your fish might be dead by then.
To tackle nitrate creep just do an extra water change in the middle of your normal interval once in a while. Alternatively you could do almost 100% WCs by filling the tank whilst draining it at the same time. Or you could do continuous drip if you have the right room setup for it.
The best way is denitrification, but unfortunately many of the fish we keep here on MFK aren't suitable for the easiest way - plants. I'll post my understanding of this next (copied from my post on another site).
The Wonderful and Mysterious World of Denitrification (Freshwater)
Please bear with me as I am a beginner fishkeeper delving into more advanced topics that I don't yet fully comprehend and have minimal experience with. From what I have read on nitrate level, and it appears most recommend < 20 for optimum fish health. Apparently there have been referenced studies on even extremely hardy fish like the fathead minnow, which can survive nitrates of 1300+ for a few days before dying, that have shown deleterious effects over time from nitrates as low as in the 20s. Between those 2 extremes, there is a spectrum of physiological adverse effects, from minimally significant to causing severe illness.
Therefore, 0 or at least < 20 PPM is ideal, 24/7.
The ways to reduce nitrates are:
Reduce ammonia (thus reducing nitrates)
- reduce feeding
- reduce stocking
- reduce mulm and detritus build up by regular gravel vaccing, and also things like the Eheim recirculating microfilter
- chemical removal eg., purigen, ammo-lock, etc
denitrification methods:
A. Water changes.
Cons:
- Dilute only, not eliminate
- Labour intensive and annoying
- Nitrate level gradually builds up, spikes, then is removed by a percentage of the water change. So for some portion of the time, nitrate level may not be ideal.
- can be disruptive and stressful to the fish, especially large ones, and especially if some characteristics of the tank water and new water dont match, thus lowering their immunity and resistance to disease.
The PERFECT solution would be a constant process of nitrate removal, preferably natural.
Please note with all of the below methods some SMALL WATER CHANGES ARE STILL NECESSARY to replace minerals lost and unmeasured toxins, but I believe regular gravel vaccing will exchange enough water for this. Some Walstad tanks have not had water changes for YEARS.
These are the options available:
B. Plants
1. In the main tank
2. In a refugium
- in the sump
- in an overflow
- in a HOB filter
Cons:
- requires compatible fish
- requires lighting and sometimes CO2
- requires sump/HOB filter, etc
As I am planning an oscar tank with canister, and don't have a sump, plants aren't really an option. The few plants that can grow in a HOB filter are probably insignificant in large fish tanks.
C. Algae
1. In the main tank (undesirable)
2. Algae scrubber, where algae is continuously grown, take up nitrates, and manually shed.
Commercial kits exist eg., hang on glass upflow with LED lighting.
Requires lighting and weekly maintenance to shed algae.
D. Denitrification bacteria (NO3 -> N2 gas)
These require anaerobic conditions so need specialized environments to survive. There are specialized media such as Seachem denitrate which by their design have an anaerobic core for these bacteria to thrive. Flow rate required is very low, < 50 GPH for anaerobic conditions. No canister has such a low flow rate.
1. Deep sand bed (DSB).
Requires 4-8" of fine grained sand, and fish that won't disturb it (not for cichlid tanks), otherwise you may get liberation of poisonous hydrogen sulfide.
2. Nitrate reactor
This looks like a protein skimmer but is full of biopolymers that anaerobic bacteria multiply on. Requires feeding the bacteria a carbon source such as alcohol (or you can even use sugar). Some top of the line models such as Deltecs have fully automated systems that feed this carbon source automatically. AFAIK this is THE most effective way to remove nitrates, achieving virtually 0 ppm 24/7, which water changes can never hope to do. However, there is a decent initial cost (about the same price as a moderate canister filter), as well as ongoings with carbon source, etc.
Sosban Fach did a great write-up about his experience with his oscar/sev tank and a Deltec nitrate reactor. His main issue was high nitrates in tap water, but the principles are the same. 100 ppm in, 0 ppm out of the filter.
http://www.oscarfishlover.com/forum/...deltec-nfp-509
E. Chemical removal
This can be of nitrate itself or of ammonia before it enters thenitrogen cycle, thus indirectly reducing nitrates.
- adsorption filters
- ion exchange resins
eg., nitra-zorb
From what I have read, these are not as effective one would think, and quite expensive to maintain/replace. Recharging them takes just as much work as doing more water changes.
In conclusion, for an oscar tank (no plants, no DSB), especially without a sump (no refugium), my choices are limited. The most effective way seems to be the virtually maintenance free nitrate reactor in order to drastically reduce BUT NOT ELIMINATE the need for water changes (would still be done during gravel vaccing debris). This will make me happier, as I do far less water changes, yet also make my fish happier, as they have a consistently, virtually nitrate free environment that reflects their wild origins eg., Amazon river 1.2 ppm nitrate, Orinoco river system even lower.
Please bear with me as I am a beginner fishkeeper delving into more advanced topics that I don't yet fully comprehend and have minimal experience with. From what I have read on nitrate level, and it appears most recommend < 20 for optimum fish health. Apparently there have been referenced studies on even extremely hardy fish like the fathead minnow, which can survive nitrates of 1300+ for a few days before dying, that have shown deleterious effects over time from nitrates as low as in the 20s. Between those 2 extremes, there is a spectrum of physiological adverse effects, from minimally significant to causing severe illness.
Therefore, 0 or at least < 20 PPM is ideal, 24/7.
The ways to reduce nitrates are:
Reduce ammonia (thus reducing nitrates)
- reduce feeding
- reduce stocking
- reduce mulm and detritus build up by regular gravel vaccing, and also things like the Eheim recirculating microfilter
- chemical removal eg., purigen, ammo-lock, etc
denitrification methods:
A. Water changes.
Cons:
- Dilute only, not eliminate
- Labour intensive and annoying
- Nitrate level gradually builds up, spikes, then is removed by a percentage of the water change. So for some portion of the time, nitrate level may not be ideal.
- can be disruptive and stressful to the fish, especially large ones, and especially if some characteristics of the tank water and new water dont match, thus lowering their immunity and resistance to disease.
The PERFECT solution would be a constant process of nitrate removal, preferably natural.
Please note with all of the below methods some SMALL WATER CHANGES ARE STILL NECESSARY to replace minerals lost and unmeasured toxins, but I believe regular gravel vaccing will exchange enough water for this. Some Walstad tanks have not had water changes for YEARS.
These are the options available:
B. Plants
1. In the main tank
2. In a refugium
- in the sump
- in an overflow
- in a HOB filter
Cons:
- requires compatible fish
- requires lighting and sometimes CO2
- requires sump/HOB filter, etc
As I am planning an oscar tank with canister, and don't have a sump, plants aren't really an option. The few plants that can grow in a HOB filter are probably insignificant in large fish tanks.
C. Algae
1. In the main tank (undesirable)
2. Algae scrubber, where algae is continuously grown, take up nitrates, and manually shed.
Commercial kits exist eg., hang on glass upflow with LED lighting.
Requires lighting and weekly maintenance to shed algae.
D. Denitrification bacteria (NO3 -> N2 gas)
These require anaerobic conditions so need specialized environments to survive. There are specialized media such as Seachem denitrate which by their design have an anaerobic core for these bacteria to thrive. Flow rate required is very low, < 50 GPH for anaerobic conditions. No canister has such a low flow rate.
1. Deep sand bed (DSB).
Requires 4-8" of fine grained sand, and fish that won't disturb it (not for cichlid tanks), otherwise you may get liberation of poisonous hydrogen sulfide.
2. Nitrate reactor
This looks like a protein skimmer but is full of biopolymers that anaerobic bacteria multiply on. Requires feeding the bacteria a carbon source such as alcohol (or you can even use sugar). Some top of the line models such as Deltecs have fully automated systems that feed this carbon source automatically. AFAIK this is THE most effective way to remove nitrates, achieving virtually 0 ppm 24/7, which water changes can never hope to do. However, there is a decent initial cost (about the same price as a moderate canister filter), as well as ongoings with carbon source, etc.
Sosban Fach did a great write-up about his experience with his oscar/sev tank and a Deltec nitrate reactor. His main issue was high nitrates in tap water, but the principles are the same. 100 ppm in, 0 ppm out of the filter.
http://www.oscarfishlover.com/forum/...deltec-nfp-509
E. Chemical removal
This can be of nitrate itself or of ammonia before it enters thenitrogen cycle, thus indirectly reducing nitrates.
- adsorption filters
- ion exchange resins
eg., nitra-zorb
From what I have read, these are not as effective one would think, and quite expensive to maintain/replace. Recharging them takes just as much work as doing more water changes.
In conclusion, for an oscar tank (no plants, no DSB), especially without a sump (no refugium), my choices are limited. The most effective way seems to be the virtually maintenance free nitrate reactor in order to drastically reduce BUT NOT ELIMINATE the need for water changes (would still be done during gravel vaccing debris). This will make me happier, as I do far less water changes, yet also make my fish happier, as they have a consistently, virtually nitrate free environment that reflects their wild origins eg., Amazon river 1.2 ppm nitrate, Orinoco river system even lower.
There is much more behind a large regular water change, than just the reduction of nitrates. I suggest you research more along that line. Not just the other substances being removed, but also those substances in the fresh tap water that are being added.
Also, there is another manner in which to reduce the organic load in ones tank, thereby reducing nitrates - probiotic bacteria.
http://monsterfishkeepers.com/forums/threads/the-use-of-probiotics-in-aquaculture.536531/
HTH
Also, there is another manner in which to reduce the organic load in ones tank, thereby reducing nitrates - probiotic bacteria.
http://monsterfishkeepers.com/forums/threads/the-use-of-probiotics-in-aquaculture.536531/
HTH
You have definitely done some resurching.
The anaerobic side of things can get complicated very fast. Mostly just the all the misinformation, and types of bacteria. The type of equipment. It also requires an education.
I have a DIY 1.5 gallon ,sugar feed anoxic gravity powered cylindrical swamp gas generator. Currently flowing at 7.5 GPD, monitored with an ORP mv meter.
The name does mater when comparing, and reading into articles.
The only problems I have encountered have been flow control and sugar feeding times.
My nitrates are kept around 5-10 ppm, my tap water is 7ppm.
An ORP mv meter, is very indispensable, and I would never be able to get 7+GPD flow with out it.
Crashing aka too much flow takes about 4 days to recover from.
Going full septic, rotten egg smell, takes about 24 hours of too low of flow. Quick rebound however.
With 1 Oscar in a well designed tank layout to prevent excess food/ waste from decomposing. Nitrate removal is do able.
The anaerobic side of things can get complicated very fast. Mostly just the all the misinformation, and types of bacteria. The type of equipment. It also requires an education.
I have a DIY 1.5 gallon ,sugar feed anoxic gravity powered cylindrical swamp gas generator. Currently flowing at 7.5 GPD, monitored with an ORP mv meter.
The name does mater when comparing, and reading into articles.
The only problems I have encountered have been flow control and sugar feeding times.
My nitrates are kept around 5-10 ppm, my tap water is 7ppm.
An ORP mv meter, is very indispensable, and I would never be able to get 7+GPD flow with out it.
Crashing aka too much flow takes about 4 days to recover from.
Going full septic, rotten egg smell, takes about 24 hours of too low of flow. Quick rebound however.
With 1 Oscar in a well designed tank layout to prevent excess food/ waste from decomposing. Nitrate removal is do able.
