Balancing Nitrate & Phosphate in SPS Tank

[Rick's Reefing Adventures]

Hey everyone,

I’ve been battling with nutrients for a while. For years my nitrates and phosphates would bottom out, and I had to dose to keep them detectable. Since adding an auto-feeder things have improved a lot, and I no longer need to dose just to keep them from hitting zero.

Recently I switched the tank from LPS to SPS, and now I’m noticing that my phosphates are running a little higher than I’d like. Current parameters:

• Nitrate: 0.5–2 ppm (weekly testing)
• Phosphate: 0.055–0.08 ppm

These numbers were fine for my LPS, but for SPS it feels a bit unbalanced—especially since the nitrate/phosphate ratio is off. Ideally, I’d like to raise nitrates a little while bringing phosphates down slightly.

At the moment, I’ve been dosing a bit of nitrate once a week to help bring the balance closer, but I’m wondering:

What are the best ways to raise nitrate while slightly lowering phosphate in an SPS tank?

Thanks in advance for the input!

 

[X-37B]

Those numbers are fine for any corals. The ratio is not needed.
I run all 4 system at po4<.1 and no3<5.

 

[Featherweight]

These numbers should be fine. No lower on po4. Might raise Nitrates a touch but no biggie

My system looks best at .1 and 10 give or take

 

[bubbgee]

Hey everyone,

I’ve been battling with nutrients for a while. For years my nitrates and phosphates would bottom out, and I had to dose to keep them detectable. Since adding an auto-feeder things have improved a lot, and I no longer need to dose just to keep them from hitting zero.

Recently I switched the tank from LPS to SPS, and now I’m noticing that my phosphates are running a little higher than I’d like. Current parameters:

• Nitrate: 0.5–2 ppm (weekly testing)
• Phosphate: 0.055–0.08 ppm

These numbers were fine for my LPS, but for SPS it feels a bit unbalanced—especially since the nitrate/phosphate ratio is off. Ideally, I’d like to raise nitrates a little while bringing phosphates down slightly.

At the moment, I’ve been dosing a bit of nitrate once a week to help bring the balance closer, but I’m wondering:

What are the best ways to raise nitrate while slightly lowering phosphate in an SPS tank?

Thanks in advance for the input!

have you used Tropic Marin Bacto-balance? That is supposedly used to balance PO4 and NO3. I've used it and it appears to work as intended.

 

[Lavey29]

Frozen food helps raise nitrates. Pellet affects phosphate. Feed more, export less.

 

[Rick's Reefing Adventures]

Those numbers are fine for any corals. The ratio is not needed.
I run all 4 system at po4<.1 and no3<5.

Oh great, I thought SPS enjoyed their phosphates near 0...

These numbers should be fine. No lower on po4. Might raise Nitrates a touch but no biggie

My system looks best at .1 and 10 give or take

Oh alright thanks!

have you used Tropic Marin Bacto-balance? That is supposedly used to balance PO4 and NO3. I've used it and it appears to work as intended.

Never heard of it! I will look into it thanks!

Frozen food helps raise nitrates. Pellet affects phosphate. Feed more, export less.

Good to know! I feed pellets twice a day and nitrate once every few days so I'll feed more frozen to see how that goes!

 

[Mongo1.0]

Love these discussions. Keep filling the Notes on my phone with his of info.

 

[exnisstech]

Numbers look good to me. As @X-37B mentioned I don't worry about ratios either.

These graph are from my acro dominant tank which is doing very well IMO

 

[Randy Holmes-Farley Verified Community Expert]

I'd personally be more worried about the low nitrate than the phosphate. This has more:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

 

[Rick's Reefing Adventures]

I'd personally be more worried about the low nitrate than the phosphate. This has more:

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
4. What targets seem reasonable? Of course, that depends on all the other factors at play, such as types of corals, availability of ammonia, particulate foods, etc. However, for a mature mixed reef, this would be how I personally would run it:

• Let nitrate float between 5 ppm and 50 ppm. I’d use gentle export in this range, such as growing macroalgae.
• Above 50 ppm, I’d begin to focus more on reducing it, by organic carbon dosing, turf or macroalgae, etc.
• Below 5 ppm, I’d begin to dose ammonia or feed more. The target level might drop lower if dosing ammonia, just like the heavy in/heavy out scenario where nitrate may not be as needed.
• Let phosphate float between about 0.06 ppm and 0.3 ppm. This range is higher than I’ve recommended in the past. I’d use gentle export in this range, such as growing macroalgae.
• Above about 0.3 ppm, I’d begin to focus more on reducing it, by turf or macroalgae, or a binder such as GFO or lanthanum (has its own risks to tangs). If a binder: GO SLOW. Turf and macroalgae will typically be slow enough.
• Below 0.06 ppm, I’d begin to dose sodium phosphate or feed more to get the level up.

I'm guessing my nitrates stay low due to my pellets. I'm going to add some more frozen in the mix to see how that helps. For now I dose it once a week which seems to work okey. I feed pellets twice a day and have barely any filtration. Activated carbon and a filter roller.

Numbers look good to me. As @X-37B mentioned I don't worry about ratios either.

These graph are from my acro dominant tank which is doing very well IMO

Oh wow that's great! I always heard SPS is low nutrients but from what I'm reading here thats a thing of the past.