Reef nutrition

NO3/PO4 Help

ddrueckh

ddrueckh

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My tank generally looks good but my coral have been browning and not growing. My numbers are as follows:

Alk 8.5
CA 440
Mg 1300
Nitrate 64+ (topped out Red Sea Pro kit)
Phosphate .17

I believe my issue is the high nitrate and phosphate. I battled 0 nitrate and phosphate for a long time. I fed heavily to get them up but obviously went to far. I have a high bio load and need to continue feeding heavily. I have a fuge with a Kessil H160 and the chaeto grows but not fast enough. I increased my auto water change from 1.5 to 3 gallons a day. I use RODI. I also have a large skimmer (Reef Octopus Regal 300-int). Should I try something else to bring nitrate and phosphate down? The tank 3 years old. Thanks for any tips.
 

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Couple things come to mind: are you supplementing trace elements your chaeto needs to thrive? ICP test results you can share? Based on your auto water change volume, you must have a sizable tank. What’s the change to the tank as a %?
 
I feed 4 cubes of mysis and about the same amount of Reef Fenzy. I also feed 1/2 to 1 sheet of nori. All this is daily. I have the following fish:

Yellow Tang
Orange Shoulder Tang
Naso Tang
Achilles Tang
6 Anthias
4 Chromis
2 Perc Clowns
Copperband Butterfly
6 Line Wrass
Blue Head Wrass
Bicolor Blenny
Neon Dottyback

I feed heavy because I feel it keeps away any aggression that the tangs may have which keeps stress down. All the fish are fat and happy!
 
NOPOX works very well for this situation (both nitrate and phosphate high). Just follow the directions and start slow.

It is basically just an organic carbon source. Your tank is likely carbon-limited right now. The bacteria and algae that grow as a result will be mostly skimmed out.

Growing macroalgae in a refugium is basically just a carbon source too- the macroalgae uses the energy from photosynthesis to make organic carbon out of CO2.
 
Squist said:
Couple things come to mind: are you supplementing trace elements your chaeto needs to thrive? ICP test results you can share? Based on your auto water change volume, you must have a sizable tank. What’s the change to the tank as a %?
Click to expand...
The tank is 240 gallons (about 280 total water volume). That’s about a 20% change a month (I don’t do AWC on the weekend because of the DOS noise). I only use Tropic Marin Part C with BRS 2 part. No recent ICP test has been done. I guess I should do one.
 
JVU said:
NOPOX works very well for this situation (both nitrate and phosphate high). Just follow the directions and start slow.

It is basically just an organic carbon source. Your tank is likely carbon-limited right now. The bacteria and algae that grow as a result will be mostly skimmed out.

Growing macroalgae in a refugium is basically just a carbon source too- the macroalgae uses the energy from photosynthesis to make organic carbon out of CO2.
Click to expand...
I have been considering NOPOX. When reading about it, people seem to be pretty mixed. From my research, it seems like it would reduce nitrate/phosphate in the redfield ratio. Being that my nitrate is 64+ and phosphate .17, it seems I would run out of phosphate pretty early into reducing nitrate. Is this correct. If so, should I dose phosphate once it gets low to keep getting nitrate to my desired level? If so, what phosphate additive should I dose when i get to that point?
 
Any recommendation on a phosphate supplement to add when I start to get phosphate limited? I don’t want to bottom out phosphate when reducing the nitrate. My ration is about 376:1 nitrate to phosphate.
N 64
P 0.17
 
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ddrueckh said:
Any recommendation on a phosphate supplement to add when I start to get phosphate limited? I don’t want to bottom out phosphate when reducing the nitrate. My ration is about 376:1 N:p.
N 64
P 0.17
Click to expand...
I just dose small amount and test every couple of days, once it gets close to your desire range just let Refugium do itself job. I never added any phosphate or nitrate supplement. Sorry I can not recommend any because I never used one.
 
JVU said:
NOPOX works very well for this situation (both nitrate and phosphate high). Just follow the directions and start slow.

It is basically just an organic carbon source. Your tank is likely carbon-limited right now. The bacteria and algae that grow as a result will be mostly skimmed out.

Growing macroalgae in a refugium is basically just a carbon source too- the macroalgae uses the energy from photosynthesis to make organic carbon out of CO2.
Click to expand...
This is really interesting. I thought that algae just consumed nitrate and phosphate. You say it creates organic carbon out of CO2. My assumption is that bacteria would use this carbon just like it would use NOPOX. Is this true? Does algae both absorb the nitrate and phosphate to grow and reduce it further by creating organic carbon that bacteria use to absorb more? That’s pretty cool.
 
ddrueckh said:
This is really interesting. I thought that algae just consumed nitrate and phosphate. You say it creates organic carbon out of CO2. My assumption is that bacteria would use this carbon just like it would use NOPOX. Is this true? Does algae both absorb the nitrate and phosphate to grow and reduce it further by creating organic carbon that bacteria use to absorb more? That’s pretty cool.
Click to expand...
When the macroalgae (or any algae for that matter) make organic carbon out of CO2 and light, they do so inside their cells, not available to outside bacteria etc. Then they absorb phosphate and nitrate from the water to match the carbon they are making, and use that for growth/metabolism. When you dose carbon in the form of NOPOX (for example), you just give the bacteria a chance to compete for the nitrate and phosphate in the water by giving them what they are limited by.
 
ddrueckh said:
This is really interesting. I thought that algae just consumed nitrate and phosphate. You say it creates organic carbon out of CO2. My assumption is that bacteria would use this carbon just like it would use NOPOX. Is this true? Does algae both absorb the nitrate and phosphate to grow and reduce it further by creating organic carbon that bacteria use to absorb more? That’s pretty cool.
Click to expand...

Algae does use nitrogen and phosphate but it uses other things just like plants do. CO2 as a carbon source as mentioned plus trace elements like iron. If anything it uses becomes limited it will slow or stop growing and even die back. I couldn't get it to grow well consistently until i started dosing trace elements. In my case i suspect it was due to low iron levels as it's the largest trace element consumed by plants and algae. Coming from a 20 yr planted tank background I learned early on how important the right mix of trace elements, dissolved CO2, and macro nutrient ratios were to *avoid* algae growth. It was a constant game of dosing adjustmant. These days I'm encouraging it (chaeto) and trying to limit it (bad algae) Saltwater feels much easier to manage to me.
 
ddrueckh said:
Any recommendation on a phosphate supplement to add when I start to get phosphate limited? I don’t want to bottom out phosphate when reducing the nitrate. My ration is about 376:1 nitrate to phosphate.
N 64
P 0.17
Click to expand...
I haven’t had to dose phosphate before, but I do have to dose nitrate. There are lots of options out there but personally I’d use a supplement made for reef tanks like Brightwell NeoPhos.

I agree with your logic about your amounts being unbalanced in the Redfield ratio etc. The thing about supplementing phosphate is that your coral only needs a tiny tiny amount to be happy, and there is always that amount being produced as waste products. Plus high nitrate isn’t nearly as troublesome as high phosphate, so you really don’t want to overdo it if you start dosing phosphate.
 
Ive yet to see myself being phosphate limited when using NoPox...typically people run GFO with it as nitrates begin to bottom out long before phosphates too (that’s what I’ve run into now, as nopox is really good at removing nitrates)
 
Thank you all for the great information. I learned a lot this morning. I will try NOPOX starting with a very low dose. I certainly don’t want to rush things. I will also test nitrate and phosphate at least weekly to monitor. Thanks again for the help!
 
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Coral reefer said:
Small awc is going to maintain parameters, not lower your nutrients. Need to do some large water changes or dose carbon and use gfo IMO.
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Like @Coral reefer said best way to get those numbers down is with large water changes. Making enough saltwater for your size tank would be a pain. There is a guy who delivers large amounts of NSW for a great price.
 
ddrueckh said:
Thank you all for the great information. I learned a lot this morning. I will try NOPOX starting with a very low dose. I certainly don’t want to rush things. I will also test nitrate and phosphate at least weekly to monitor. Thanks again for the help!
Click to expand...
Me too! Good thread!
 
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