P&N Ratios Balancing the Equation

[Treefer32]

The discussion on false Nitrate readings based on nitrite presence got me thinking about my "issues". Now, the good thing is that most of my 340 gallon mixed reef is not showing any signs of distress! So, the visible check... Things are good. Acros are growing. Duncans wide open. Hammers and Frog spawn all happy for the moment. So, a huge check mark, nothing is visibly wrong!

That said, my tank is 4 years old and over that time I've seen coral recession happen rapidly and suddenly as soon as Phosphates or Nitrates crept up too high. I'm taking a watch and test methodology to it right now and implementing small changes.

The last time I tested, my Nitrates were 34ppm (Hanna High range tester) and phosphates @ .18 ppm. The week before N was 29 and P was .12. Nearly a 33% increase in a 7 day period of both.

Exports:
Filter roller
Algae turf scrubber
Oversized skimmer (Rated for Moderate load for 500 gallon tank)
I've just implemented a pelletized nitrate reactor
I converted a cannister filter to a denitrator (Been operating for 2 months) with Matrix rock init
I've also been vodka dosing 30 ml per day

The biggest symptom I've noticed now, is my algae turf scrubber growing so much slower. It used to be full of hair algae in under 6 days. Now, it's taking 2 weeks (maybe longer) to fill in and mostly with a combination of hair and slime algae.

My glass fills in with film algae within 2-3 days of scraping.

No visible signs of algae on any rocks or sand, no signs of cyano either.

I'm going to take the vodka offline since implementing the pellet reactor after the 3 week break in period is done.

If I get a nitrite test, is it possible my ATS is suffering because my nitrates are actually close to 0 and Nitrites are giving a false reading on the nitrate test? I'm wondering what hypothesis to test. So I don't change too much and/or implement the wrong solution.

I feed heavy both coral and home made frozen fish food. I have around 20 fish, many of them large. My Dragon Wrasse is around 8 inches long, my Caribean blue tang is bordering on too large for my tank at 10-11" in diameter. Lamarcks angelfish that's fat and probably 7" long. Two other fat and happy tangs, etc.

I feet a whole sheet of nori per day plus around 1-2 oz of frozen food per day and most of all of it is eaten by the fish everyday within minutes.

 

[Randy Holmes-Farley]

On the title, I think balancing the P to N ratio is not a useful concept, but making sure you have enough nitrate is, which at 34 ppm is almost certainly plenty/more than enough using the Hanna kit since it's interference from nitrite is on the lower side compared to some kits.

 

[Treefer32]

On the title, I think balancing the P to N ratio is not a useful concept, but making sure you have enough nitrate is, which at 34 ppm is almost certainly plenty/more than enough using the Hanna kit since it's interference from nitrite is on the lower side compared to some kits.

So, if I'm understanding correctly. Due to the amount of nitrate detected.. Even if there were some interference from nitrites. The amount would be so small, that actual nitrates might be 30 vs. 34. etc.

That's really good information to have. I agree that balancing the Red field ratio is not so important. I haven't tried. I think in artificial environments with different filtration impacting various variables of the equations, it may be impossible to synthesize nature's processes in a closed environment.

That said, If N&P are actually present and not false positives. Saying P is between .12 and .20 and Nitrates are currently between 30 and 40.

Why would my ATS slow hair algae production? The lights on 24/7, screen is cleaned thoroughly everytime it's full. It's been producing massive amounts of hair algae every 7-10 days. Up until the last month or so.

 

[Eagle_Steve]

So, if I'm understanding correctly. Due to the amount of nitrate detected.. Even if there were some interference from nitrites. The amount would be so small, that actual nitrates might be 30 vs. 34. etc.

That's really good information to have. I agree that balancing the Red field ratio is not so important. I haven't tried. I think in artificial environments with different filtration impacting various variables of the equations, it may be impossible to synthesize nature's processes in a closed environment.

That said, If N&P are actually present and not false positives. Saying P is between .12 and .20 and Nitrates are currently between 30 and 40.

Why would my ATS slow hair algae production? The lights on 24/7, screen is cleaned thoroughly everytime it's full. It's been producing massive amounts of hair algae every 7-10 days. Up until the last month or so.

Possible lack of trace elements? I have macro tanks, and without addition of trace elements things go to crap. Now being as mine are macro tanks, I go through cheatogro like reefers go through alk lol.

It might be worth it to get an ICP test, or you can get some cheatogro and dose it at about 1/5 of the recommended dosage as a test to see if algae production increases.

 

[Randy Holmes-Farley]

So, if I'm understanding correctly. Due to the amount of nitrate detected.. Even if there were some interference from nitrites. The amount would be so small, that actual nitrates might be 30 vs. 34. etc.

That's really good information to have. I agree that balancing the Red field ratio is not so important. I haven't tried. I think in artificial environments with different filtration impacting various variables of the equations, it may be impossible to synthesize nature's processes in a closed environment.

That said, If N&P are actually present and not false positives. Saying P is between .12 and .20 and Nitrates are currently between 30 and 40.

Why would my ATS slow hair algae production? The lights on 24/7, screen is cleaned thoroughly everytime it's full. It's been producing massive amounts of hair algae every 7-10 days. Up until the last month or so.

Nitrate might possibly be less than 30, but not less than what I'd consider OK, which is a few ppm.

If both of your values were accurate as written, they are both higher than I generally recommend.

macroalgae needs lots of things, including lots of different trace elements such as iron and manganese, and these can be limiting, as can other things sch as lighting, flow, herbivores, etc.

 

[Treefer32]

I'm dosing alk and All for reef. I took magnesium off line due to dosing with all for reef. All for reef contains all trace elments, including alk, calcium, and magnesium. But it's insufficient to maintain alk. That said Taking my magnsium chloride / sulfite mix offline does coincide with the slow down of my algae scrubber. I had not thought about that.

My alk consumption has gone down significantly. I mean significantly. I was dosing 240 ml per day of my baked baking soda mix and calcium mix. After testing and watching alk rise I slowed my dosers down to let it come down. I've stopped dosing the red sea trace elements A, B, C, and D due to dosing all for reef. I was doing 30 ml per week of each (once a week).

Now I'm only dosing 60 ml per day of all for reef and I'm down to 48 ml per day of alk. The alk consumption slow down also coincides with my scrubber slow down. I have more corals than I had before, and alk consumption slowed.

The good thing is alk is not fluctuating much per day at my current dosing.

Maybe I continue to dose Magnesium (lower dosage than I was doing) and dose trace elements at a lower dosage).

 

[sixty_reefer]

The discussion on false Nitrate readings based on nitrite presence got me thinking about my "issues". Now, the good thing is that most of my 340 gallon mixed reef is not showing any signs of distress! So, the visible check... Things are good. Acros are growing. Duncans wide open. Hammers and Frog spawn all happy for the moment. So, a huge check mark, nothing is visibly wrong!

That said, my tank is 4 years old and over that time I've seen coral recession happen rapidly and suddenly as soon as Phosphates or Nitrates crept up too high. I'm taking a watch and test methodology to it right now and implementing small changes.

The last time I tested, my Nitrates were 34ppm (Hanna High range tester) and phosphates @ .18 ppm. The week before N was 29 and P was .12. Nearly a 33% increase in a 7 day period of both.

Exports:
Filter roller
Algae turf scrubber
Oversized skimmer (Rated for Moderate load for 500 gallon tank)
I've just implemented a pelletized nitrate reactor
I converted a cannister filter to a denitrator (Been operating for 2 months) with Matrix rock init
I've also been vodka dosing 30 ml per day

The biggest symptom I've noticed now, is my algae turf scrubber growing so much slower. It used to be full of hair algae in under 6 days. Now, it's taking 2 weeks (maybe longer) to fill in and mostly with a combination of hair and slime algae.

My glass fills in with film algae within 2-3 days of scraping.

No visible signs of algae on any rocks or sand, no signs of cyano either.

I'm going to take the vodka offline since implementing the pellet reactor after the 3 week break in period is done.

If I get a nitrite test, is it possible my ATS is suffering because my nitrates are actually close to 0 and Nitrites are giving a false reading on the nitrate test? I'm wondering what hypothesis to test. So I don't change too much and/or implement the wrong solution.

I feed heavy both coral and home made frozen fish food. I have around 20 fish, many of them large. My Dragon Wrasse is around 8 inches long, my Caribean blue tang is bordering on too large for my tank at 10-11" in diameter. Lamarcks angelfish that's fat and probably 7" long. Two other fat and happy tangs, etc.

I feet a whole sheet of nori per day plus around 1-2 oz of frozen food per day and most of all of it is eaten by the fish everyday within minutes.

Imo you maybe interpreting the ratio in a wrong way, the redfield ratio is more on how bacteria in general will consume nutrients in an environment, in a closed system you could use that as a guideline. The reason you may be seeing a slowdown on the growth of your algae bed is most likely because your tank is well balanced at the moment with the biological filter, leaving less nutrients available for the algae.

 

[Dan_P]

The discussion on false Nitrate readings based on nitrite presence got me thinking about my "issues". Now, the good thing is that most of my 340 gallon mixed reef is not showing any signs of distress! So, the visible check... Things are good. Acros are growing. Duncans wide open. Hammers and Frog spawn all happy for the moment. So, a huge check mark, nothing is visibly wrong!

That said, my tank is 4 years old and over that time I've seen coral recession happen rapidly and suddenly as soon as Phosphates or Nitrates crept up too high. I'm taking a watch and test methodology to it right now and implementing small changes.

The last time I tested, my Nitrates were 34ppm (Hanna High range tester) and phosphates @ .18 ppm. The week before N was 29 and P was .12. Nearly a 33% increase in a 7 day period of both.

Exports:
Filter roller
Algae turf scrubber
Oversized skimmer (Rated for Moderate load for 500 gallon tank)
I've just implemented a pelletized nitrate reactor
I converted a cannister filter to a denitrator (Been operating for 2 months) with Matrix rock init
I've also been vodka dosing 30 ml per day

The biggest symptom I've noticed now, is my algae turf scrubber growing so much slower. It used to be full of hair algae in under 6 days. Now, it's taking 2 weeks (maybe longer) to fill in and mostly with a combination of hair and slime algae.

My glass fills in with film algae within 2-3 days of scraping.

No visible signs of algae on any rocks or sand, no signs of cyano either.

I'm going to take the vodka offline since implementing the pellet reactor after the 3 week break in period is done.

If I get a nitrite test, is it possible my ATS is suffering because my nitrates are actually close to 0 and Nitrites are giving a false reading on the nitrate test? I'm wondering what hypothesis to test. So I don't change too much and/or implement the wrong solution.

I feed heavy both coral and home made frozen fish food. I have around 20 fish, many of them large. My Dragon Wrasse is around 8 inches long, my Caribean blue tang is bordering on too large for my tank at 10-11" in diameter. Lamarcks angelfish that's fat and probably 7" long. Two other fat and happy tangs, etc.

I feet a whole sheet of nori per day plus around 1-2 oz of frozen food per day and most of all of it is eaten by the fish everyday within minutes.

Consider dosing trace elements. Vigorously growing algae can deplete these elements quickly and thoroughly.

 

[Garf]

Consider dosing trace elements. Vigorously growing algae can deplete these elements quickly and thoroughly.

The OP is feeding a sheet of nori every day. I guess the question would be, how much of these bound nutrients are available for new algal growth? I know iron used to be blamed for poor algal growth on scrubbers, way back. Is released iron from foods actually available? @Randy Holmes-Farley has a diy iron recipe on here somewhere. Basically an iron supplement tablet squished into RODI, then dose the clear stuff.

 

[Garf]

I would also add, there were lots of failed scrubbers attributed to carbon dosing. The reason for that was unidentified, it certainly wasn’t low N & P. Perhaps promotion of pathogens to algae, bacteria locking up micronutrients, dunno.

 

[Dan_P]

The OP is feeding a sheet of nori every day. I guess the question would be, how much of these bound nutrients are available for new algal growth? I know iron used to be blamed for poor algal growth on scrubbers, way back. Is released iron from foods actually available? @Randy Holmes-Farley has a diy iron recipe on here somewhere. Basically an iron supplement tablet squished into RODI, then dose the clear stuff.

It depends on how fast the trace elements are being depleted. I also fed one 8x8 inch sheet of dried algae per day and that did not help my Ulva.

Dosing iron might help, but it might just as well have no effect if it is not the limiting element. ICP will be of little use here. A bit of careful experimentation is probably needed when the lucky guesses don’t pan out

 

[sixty_reefer]

The op may need to update the current parameters also, at the beginning of the thread he mentioned 34ppm nitrate and a few lines down he says that nitrate is close to zero. That could be one of the things contributing for the algae bed slow growth

 

[Garf]

I have noticed that one or two you tubers have proposed a ratio of 100:1 or 200:1 N&P. Where the heck have them figures come from, lol. Personally ratios make no sense to me, if your looking at limiting factors.

 

[sixty_reefer]

I have noticed that one or two you tubers have proposed a ratio of 100:1 or 200:1 N&P. Where the heck have them figures come from, lol. Personally ratios make no sense to me, if your looking at limiting factors.

They YouTubers they don’t know what they saying 99% of the time. If you don’t know your Carbon those ratios don’t mean anything,

 

[Dan_P]

I have noticed that one or two you tubers have proposed a ratio of 100:1 or 200:1 N&P. Where the heck have them figures come from, lol. Personally ratios make no sense to me, if your looking at limiting factors.

5:0.05, 10:0.1, 20:0.2, 30:0.3, etc are all 100:1. My guess is that 5:0.05 would not grow algae the same as 30:0.3. Whenever someone proposes a ratio they must anchor the ratio by providing a concentration for one of the numbers.

 

[Randy Holmes-Farley]

5:0.05, 10:0.1, 20:0.2, 30:0.3, etc are all 100:1. My guess is that 5:0.05 would not grow algae the same as 30:0.3. Whenever someone proposes a ratio they must anchor the ratio by providing a concentration for one of the numbers.

Or, just forget that ratios exist. lol

 

[Dan_P]

Or, just forget that ratios exist. lol

OK! Dimensionless ratios are right out unless you are a chemical engineer.

 

[Randy Holmes-Farley]

OK! Dimensionless ratios are right out unless you are a chemical engineer.

On second thought, maybe we can keep specific gravity. lol

 

[sixty_reefer]

5:0.05, 10:0.1, 20:0.2, 30:0.3, etc are all 100:1. My guess is that 5:0.05 would not grow algae the same as 30:0.3. Whenever someone proposes a ratio they must anchor the ratio by providing a concentration for one of the numbers.

I feel that if only N and P are mentioned is more of a parameters discussion than a ratio discussion, parameters this days are very relaxed. The discussion that we should have more is the ratio that a environment or a closed system use/transform C N P. The main thing in our tanks that balances C N P is bacteria followed by algae, coral and tank inhabitants. If this ratios were widely known we could have less issues balancing our tank regarding of parameter levels chosen to run the system.

 

[Randy Holmes-Farley]

I feel that if only N and P are mentioned is more of a parameters discussion than a ratio discussion, parameters this days are very relaxed. The discussion that we should have more is the ratio that a environment or a closed system use/transform C N P. The main thing in our tanks that balances C N P is bacteria followed by algae, coral and tank inhabitants. If this ratios were widely known we could have less issues balancing our tank regarding of parameter levels chosen to run the system.

How would you use knowledge of the C N P ratio? I have a hard time seeing an application.

Knowing organic C doesn't say anything about whether that organic material is easily metabolized or not.