Fix high phosphate? Chase or leave

[NancyFish]

My tank seemed stable since summer (end of Dino battle & silicate dosing). Because of dosing, I wasn’t checking my phosphate. I did a big water change maybe a month ago & it triggered light cyano all over the rocks. My phosphate (which I assume should be accurate by now) is reading .19 for the past at least 3 weeks.

My nitrate which used to hang around 12 has been steady around 7, despite more fish & feeding (mix of dry pe pellets & algae max pellets).

My alk is also high around 10.8 - but this is my fault because my reagent must have been high and I was dosing more than needed. New reagent proved that, and I’ve been letting it drop before dosing again. Only dosing pns probio bacteria.

Thing is, my phosphate isn’t moving and seems really unbalanced. Not sure the best course to get the tank back to equilibrium again? I only run a roller mat, no skimmer & my sand has poor flow if that matters.

 

[Sam7]

you said: "despite more fish & feeding (mix of dry pe pellets & algae max pellets)."

Thats most of your problem....i wouldnt recommend feeding pellets to your fish. Maybe not add more fish until your can figure out why your phosphates are going up. Do more water changes more frequently, dont feed pellets... try frozen food instead and dont over feed. MAybe also increase you flow....but most of all show us your tank under white lights

 

[Randy Holmes-Farley]

That phosphate level is within my target range:

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...

www.reef2reef.com

From it:

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.

 

[NancyFish]

That phosphate level is within my target range:

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...

www.reef2reef.com

From it:

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.

Isn’t the imbalance of high phosphate and lower nitrate the reason for tiny patches of cyano on the rocks tho? Isn’t it not ideal to have that even if numbers are not super harmful individually to coral?

 

[reefmaster70]

if your tank looks good, let it ride....do your regular water changes, and call it good. I have Pukani rock in my 75g tank and I stopped trying to get my PO4 under .1 many moons ago. My tank corals (including a few sps, many torches, and goni's and Acans) all look wonderful and are happy at my current levels. My Nitrates sit between 15-18 ppm and my Phosphorous is around 105ppb (phosphate of about .32ppm). my Magnesium I keep at 1420. SG of 1.026, temp of 78.2 and pH of 8.0

HTH