What is the general consensus to what is considered UNLS?

TMC1313 · Oct 25, 2018

For a reef tank to be considered UNLS what is the general consensus? Should nitrates and phosphates be undetectable or is there a cutoff of detectable readings? For example, if nitrates are 3ppm and phosphates are .02ppm, is that considered UNLS? Just curious, as I see a lot of posts about UNLS and alkalinity issues, but I don't really see what levels are considered to be such. Are there other factors beside nitrate and phosphate that come into play when determining if a system is UNLS?

Reeferdood · Oct 25, 2018

zero and zero would be UNLS, I am not a fan of this method whatsoever. It takes way too much fun out of the hobby when you try maintaining zero levels. Most keep there nitrates @20 and phosphate @.06
There are some exceptions but most all of the real big boys keep their water a little dirtier than ULN..

Randy Holmes-Farley · Oct 27, 2018

IMO, phosphate below 0.01 ppm and nitrate below 0.5 ppm or so is too low for optimal reef tank performance, unless you are taking very high care with foods that supply N and P to organisms.

Reeferdood · Oct 27, 2018

Randy Holmes-Farley said:
IMO, phosphate below 0.01 ppm and nitrate below 0.5 ppm or so is too low for optimal reef tank performance, unless you are taking very high care with foods that supply N and P to organisms.

Good to see you are still lurking about from time to time sir...