Yet Another "I am close to giving up" Thread

Read through all of the above - and I agree, this may have to do with an imbalance in N/P/alk, but I'm not sure why.

I agree with the entire post you made, Tripod - what is confounding is why I still had zero growth shown when N/P = 0 and alk was where it should be. This is the low/low/low side of the equation, and was maintained for well over a year; only lately have I been playing around with increasing my N/P.

I've been working more towards feeding heavily (the "P" side) and raising N via NaNO3, with alk still in that range of 8-8.3. I suppose I could try to raise it up once I have detectable phosphates, but I'm worried that will just confound the issue.

Guess I'm back to the testing phase for another 3+ months, while trying to get N/P stable at 5PPM / 0.03ppm respectively, while slowly raising alk to 9.0 or so.

Colton

Coltan, N/P ~ 0 and low alk only works if you somehow feed the corals. It is generally not easy to feed SPS corals, you would literately need to turn water cloudy with coral food for them to get enough. People do N/P ~ 0 and low alk on zeovit tanks but, they also feed their corals. They either feed plankton, or bacteria from the zeovit reactor (which turns the tank cloudy). Plus they add bunch of additives to the tank like amino acids and other micro nutrients. Even then growth of corals are very very slow in zeovit tanks.

In nature N/P ~ 0 (keep in mind it is never zero in nature, misuse of GFO can drive it much lower in a tank compared to nature)and low alk also works but corals get good supply of plankton. Some days reefs can become cloudy because of plankton influx. Also the N/P ~ 0 in nature is more like an average. There can be certain days or weeks that currents bring nitrate and phosphate rich water. When that happens, corals suck up the nutrients. Below you can find an article written on that subject with primary literature.

Corals and algae on coral reefs rapidly take up phosphate from the ambient sea water as it is available. In fact, it’s been shown that coral reefs tend to suck up phosphate as fast as it is physically possible to do so (Falter et al., 2004). In places like the barrier reef flat in Kāne‘ohe Bay, Hawai‘i—which is a very wide reef flat at about 1.5 miles (2.4 km) across—the reef is able to suck phosphate out of the water so effectively, it creates “ultra-oligotrophic” conditions as sea water passes over it (M. Atkinson, pers. comm.). Here it is not unusual to find phosphate concentrations at the very lower limit of scientific detection—on the order of 0.005-0.01 µM, or 0.0005-0.001 ppm. This is a much lower phosphate concentration than can possibly be detected using hobbyist grade test kits.

https://reefs.com/magazine/skeptical-reefkeeping-ix-130/

So coral reefs have very low phosphate partially because they such up all the phosphate. If we could look at the system dynamically, we would see a constant stream of phosphate that is taken up very fast. In a tank, when you make strip phosphate with GFO or some other mechanisms, you starve corals because you only generate the final outcome. In tanks we do not have a stream of phosphate coming in, to replicate that artificially we would need constantly drip phosphate to the tank while using GFO to remove the excess phosphate not taken up by the coral.
 
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Hey Charlie - While I wouldn't rule anything out, I certainly wouldn't expect a metal contamination to have lasted as long as it has. No bare metal is in the system at all, nor is any able to come into contact.

SDE - agreed, although I was under the impression low nutrients + low alkalinity worked well also - and that there was enough to sustain corals, even if not necessarily showing on a PPM threshold. Guess this may be incorrect, and I'll start shooting for more heavy feeding / maintenance of PO4 around 0.03 along with nitrate at 5ppm.

I'll keep trying.. what is an extra few hundred in dead frags, anyways. :worried:

Colton
 
Sometimes I think people in this hobby want to over complicate things. KISS is a good rule to follow when troubleshooting a problem. So many variables in your setup.
 
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