Nitrate & Phosphate Levels

[Randy Holmes-Farley Verified Community Expert]

Have you tried sending in your water to be tested? It's famously difficult for one to be able to read nitrates at an accurate level with hobby level kits. I'd be interested in knowing what your actual levels are at. I haven't looked much into ICP testing for nitrates, but maybe @Randy Holmes-Farley will have more to say on that.

ICP cannot quantify nitrate (ICP only counts atoms, and nitrate, with N and O has many atoms in common with other things, such as N2 and O2 gases, many organics, ammonia, etc.).

But ICP companies may provide other testing services that give the nitrate value.

 

[Alan Sunshine]

I have an 10 year old tank and my phosphates continue to run at .25. That is despite a refugium with 12 hrs of grow lighit, GFO changed every 3 weeks, and intermittent Phosphate E. I feed 2-3 times a week with 2 cubes. Reef Roids 2x/week. Is this "old tank syndrome" and I should remove all rock and sand?

 

[Randy Holmes-Farley Verified Community Expert]

I have an 10 year old tank and my phosphates continue to run at .25. That is despite a refugium with 12 hrs of grow lighit, GFO changed every 3 weeks, and intermittent Phosphate E. I feed 2-3 times a week with 2 cubes. Reef Roids 2x/week. Is this "old tank syndrome" and I should remove all rock and sand?

I wouldn't remove rock and sand.

If phosphate reduction was an important goal, I'd just keep increasing the export with GFO or possible lanthanum.

Reef roids are said to boost phosphate more than other foods, but I've not seen actual data.

What is the measured nitrate?

 

[Alan Sunshine]

Phosphates .25, Nitrates 5.2

 

[Randy Holmes-Farley Verified Community Expert]

Phosphates .25, Nitrates 5.2

OK, so the nitrate (if accurate) is not limiting the macroalgae.

 

[Alan Sunshine]

I cleaned out my refugium again last night and I repeated my Hanna tests this evening. I am happy to report my PO4-0.08 and my N03-4.6. I am a little surprised by grateful at the result. If this is correct, will I see regression of Cyano on the live rock and Diatoms on the sand? How long will it take

 

[Randy Holmes-Farley Verified Community Expert]

I cleaned out my refugium again last night and I repeated my Hanna tests this evening. I am happy to report my PO4-0.08 and my N03-4.6. I am a little surprised by grateful at the result. If this is correct, will I see regression of Cyano on the live rock and Diatoms on the sand? How long will it take

Diatoms usually die out if you do not have a significant source of silicate, such as tap water or by dosing it.

Cyano can be a tough problem that nutrient levels alone do not always solve. Check the many thread on what to do, which includes manual removal, more flow, fewer organics in the water, and in difficult situations, an antibiotic.

 

[Screwgunner]

Algea turf scubber . .03 to .05 phosphates right now I am at .2 nitrates. But it goes up when I harvest algea. If I leave it to long I will get double 0's