0 nutrients after dosing NeoPhos and NeoNitro


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Jun 6, 2020
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Charlotte, NC
My phosphates are stuck at 0. I am dosing enough NeoPhos to raise it by 0.03 daily for 3 days now (as per instructions on the bottle). According to Hanna phosphorus ulr test kit, my tank takes up 0.20 phosphate per day (I had a spike for 2 days form a fish death, sand burrowing wrasse that got fully consumed my tank cuc). It’s a 25 lagoon started with live rock form the gulf.

Is my system carbon limited? How can I know if my system is carbon limited? I dose tropic marine all for reef (my phosphates went to 0.006 and eventually 0 once I started dosing it. It was previously at 0.012). Alk consumption is 0.2 dkh per day.

I am also going through a cyano outbreak now. Dose that have an effect on my nutrients? Nitrate is undetectable as well (granted that I use API test kit for that).

@Randy Holmes-Farley

Randy Holmes-Farley

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Sep 5, 2014
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Arlington, Massachusetts, United States
Just dose more if the values are not coming off zero. Most tanks are carbon limited for bacteria, but that has no bearing on N and P being low.

Yes, cyano is consuming some of the nutrients, as will other organics and binding of phosphate to the rock and sand.

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