Nitrate and Phosphate Levels

[Jblaine]

I have a new aquarium that has a high nitrate level of 37.6 ppm and phosphate at .36 ppm. It has been running for about 5 months. What is the best way to lower nitrate? No algae showing yet and fish seem good. No corals in the system yet and have started cutting back on the feeding. Should I use NoPox and/or GFO? I have also been looking into a refugium

Thanks
Jon

 

[Fish Fan]

Here's Randy's advice for target levels:

Randy’s Thoughts on Nutrient Target Ranges

Thoughts on Nutrient Target Ranges by Randy Holmes-Farley Almost nothing in the world of reef aquarium chemistry causes as much discussion as selecting and maintaining ranges for nitrate and phosphate. Some aquarists want low targets, some want high targets, some want a particular ratio, and...

www.reef2reef.com

From the above:
"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."

Based on the above, your nitrate is fine and your phosphate is but a touch high

I hope this helps!

 

[Randy Holmes-Farley]

As noted above, the levels are not a big issue, but if you want to lower nitrate, organic carbon dosing (I prefer vinegar) is a fine way to go.

GFO is one of several ways to reduce phosphate if that is your goal.