[Boomer]

Almost exactly true Carlo and you reading into things again that are not there. Those levels Marc has are way beyond any affect as far as Nitrate up take goes and any limiting effect for any form of marine life using nitrate. Excessive levels way above any normal or even above normal liming will not be affect buy rapid drops. We are not talking here about dropping them to ZERO, another issue. If you want to argue 1ppm, as being excessive and dropping them quickly them maybe. And remember that data in the article is from lab tests and is not from full blown reef tanks, another whole issue.

As far as WC goes 1,000's of people have done large multiple WC as I, Randy or many others have suggested with no such effects as you have claimed. 1000's of people do 25-30 % WC / m and is what Randy often suggests to keep ions in balance for sup additions. Your probably were doing something wrong if you had such problems. You need to go back to Randy's article and LOOK at the NO3- levels he is discussing, we are talking for corals NO3 that even <1 ppm is excessive.

Excessively high nitrates are not good for corals and has been shown many times. I have yet seen any tank have problems or even someone mention having problems from dropping high nitrate levels other than yours unless it is a Marco algae tank. I see little of any real problematic algae in his tank.

Nitrate is not the only carbon source that plants and animals use and they are rarely limited in a reef tank for carbon sources. And looking at a pic of his tank does not tell anyone anything about the health of his tank.

So changing this level fast wipes out their food source and a quick die-off can contribute to other problems which aren't easy to identify

No they do not unless they are limited. And most tanks are by far not limited with a large WC. And Marc dropping his NO3- from 30 to say 10 or 5 ppm will do nothing. And as far as AZNO3 -
or the addition of Vodka they may be more of a problem if you are not careful, more than any large water change, as they fuel bacterial growth and if fueled enough will bring on rapid bacterial growth on fish and can eve kill them. This was recently shown at MACNA.


That is a pretty high Alk Marc, like 4.5 meq / l