Another example why some over rate nutrient levels…

[CHSUB]

My tank runs po4 ~.02 Hanna, and no3 undetectable Salifert. Yesterday while cleaning my AIO sump, in the final chamber I noticed large amounts of sponges, many as large as a half dollar. This area the tank water goes through a filter sponge, fine filter sock, protein skimmer and GAC. Assuming this water is the cleanest water my tank has and it still supports non-photosynthesis organisms, why run nutrients any higher that NSW? Sponges are consuming something other than inorganic nutrients that many insisted are in short supply in glass boxes, not sure that is true?

 

[Randy Holmes-Farley Verified Community Expert]

Nonphotosynthetic sponges consume organic matter. In that organic matter they get N and P, just like a fish. I’m not sure they take in and use any inorganic nutrients. They may well be a source of inorganic nutrients.

 

[CHSUB]

Nonphotosynthetic sponges consume organic matter. In that organic matter they get N and P, just like a fish. I’m not sure they take in and use any inorganic nutrients. They may well be a source of inorganic nutrients.

Yes. I’m thinking we are underestimating the amount of organic matter in the aquarium, despite filtering these sponges are thriving. Would assume corals in DT have a larger amount to feed on, assuming they feed on the same stuff. Not speaking of zooxanthellae, the corals themselves..hence no real need to elevate inorganic nutrients beyond NSW?

 

[Randy Holmes-Farley Verified Community Expert]

Yes. I’m thinking we are underestimating the amount of organic matter in the aquarium, despite filtering these sponges are thriving. Would assume corals in DT have a larger amount to feed on, assuming they feed on the same stuff. Not speaking of zooxanthellae, the corals themselves..hence no real need to elevate inorganic nutrients beyond NSW?

I dont know the relative need or ability of corals to use doc and POC relative to sponges, but sponges seem designed to filter water more aggressively than corals.

 

[p1u5h13r4m24]

I wouldn’t say overrated. I spent my first few years of this hobby struggling. The advice I followed was keep your nutrients as low as possible. Needless to say nothing survived in my tank and I could never understand why. IMO low nutrients is a bit more dangerous when it comes to nutrients. I feel like a bit more elevated and more importantly balanced will guide one in the right direction.

 

[CHSUB]

spent my first few years of this hobby struggling

You would probably have struggled in the “first few years” regardless of your tanks nutrient levels?

IMO low nutrients is a bit more dangerous when it comes to nutrients. I feel like a bit more elevated and more importantly balanced will guide one in the right direction.

Imo, there is no danger from low nutrients that could be diagnosed with hobby test kits. Zeros on hobby kits are fine, imo; pale, weak corals and no algae are the only symptom of low nutrients.