High nitrate

[TMuchi]

I've had an aquarium set up for 1 year and 4 months. Since I started it, I've been having problems with high nitrate levels; only nitrate, phosphate, stays around 0.05.

System: 270L, Oceantech substrate, Maxspect Nano Sphere 2L media, TMC 750 skimmer, 8000L/h return pump.

Fish: 2 Clownfish.

1 Yellow Watchmen.
1 Grammistes.

1 Yellow Coral Goby.

1 Green Coral Goby.

1 Dancer Goby.

LPS and Soft Corals: Torch Trumpet

 

[Fish Fan]

What is your nitrate concentration?

 

[TMuchi]

What is your nitrate concentration?

50ppm

 

[Fish Fan]

That's right at the top range of Randy Holmes-Farley's recommendation for nitrate. If your tank is looking good, I probably wouldn't worry about it too much.

Here's Randy's post on nutrient target ranges:
https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/
From that post:
"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 think you're likely fine, but if it gets any higher you can try to add some macro algae in your display, refugium, or by adding an algae turf scrubber. Carbon dosing is another great option to lower nitrate without dropping phosphate further.

I hope that helps, good luck!

 

[BryanM]

I wouldn't worry too much there, there's a bunch of successful systems dirtier than that.

I would try to keep it from increasing at this point, and maybe try to decrease it a little, but generally that's fine.

 

[PharmrJohn]

I ran higher than that and did just fine. I eventually put in a denitrator and my nitrates did go down. But overall I didn't see much of a difference between my old readings and the new.