Hi all,
It's strange Patrik that you argue different things in different places and that the references you yourself gave when you started your nano all point to exactly what Tom is saying here. Did you not read the references you yourself cite? Based on those references you made alot of claims on this issue. Later you backed from the cleary incorrect ones. I have seen few "reefers" dispute your theoretically sound claims. Myself and several more even back you plausible ones.

I have seen no experimental data that high levels of NO3 limit the process of calcification, and I mean the chemical process itself.

In the case of Macros the study you cited about macroalgae indicates that non calcifying macroalgae may outcompete calcifying when N and P is dosed. That again has nothing to do with the depositing of CaCO3 itself, only the relative competitiveness of the different algae.

There is however significant experimental data that points to the fact that high levels of NO3 has negative effects on the coral as a whole. Theorized by some that nitrogen is used by the coral to manage its zooxanthellae. High levels of NO3 leading to zoox. overcrowding, coral browning, and also coral bleaching, coral ejecting it's zoox.. Stressed corals calcify less. Again, no direct connection between NO3 and calcification. Also there is the theory on CO2 limitation in the coral, reducing calcification, from higher zoox. activity as in your cited article Patrik.

You have disputed this, Patrik, in the past and I have understood that you changed your mind. Do you again argue that high levels of NO3 does not affect a coral? Tom, your position?

When I discuss with other "reefers" on reef forums I argue that a higher nitrogen flux is necessary. In starved systems, heavily skimmed, that means holding a measurable nitrogen level. In "high-bio" systems, like the nanos of Lasse Forsberg or Eric Bornemans skimmerless tanks, that flux comes from organic nitrogen. Mostly from bacterial biomass. This also implies dosing may be necessary in some cases.

You have also seen me argue in many places that NO3 may have to be dosed in starved reef systems using macroalgae as the primary export. This is to offset the relatively few N export paths in comparison with P export paths. I have backed your nano experiment since it's interesting at least from this perspective.

Noone of note is disputing your sound claims or trying to stop you from carrying out your interesting experiments. Several are arguing against your clearly incorrect claims. You have also, as I interpret your results, empirically proven some of your own claims to be false. Because we do not agree with you to 100% does not mean we disagree. In fact I'm still very much interested in your experiments.
//Mattias

P.S. These where the references given by Patrik during the onset of a long debate on a swedish forum about dosing in the presence of corals.

1. Coral growth in high-nutrient, low-pH seawater: a case study of corals cultured at the Waikiki Aquarium, Honolulu, Hawaii

SpringerLink - Journal Article

4. The Effect of External Nutrient Resources on the Population Dynamics of Zooxanthellae in a Reef Coral

http://links.jstor.org/sici?sici=008...2.0.CO%3 B2-X

2. Effects of Elevated Nitrogen and Phosphorus on Coral Reef Growth

http://links.jstor.org/sici?sici=002...3E2.0.CO%3B2-0

1. Nitrate increases zooxanthellae population density and reduces skeletogenesis in corals

SpringerLink - Journal Article

1. Nutrient-limited productivity of calcareous versus fleshy macroalgae in a eutrophic, carbonate-rich tropical marine environment

SpringerLink - Journal Article