Hello from France

[Pomma]

Hi everyone,

Thomas here, from France. I have been reading the forum for a while and finally made an account.

Bit of an odd introduction: I do not keep a tank, my dad doe tho. I am a software developer and I got into this sideways, through ICP data. I got curious about the fact that every lab publishes results in its own format with its own reference ranges, and I have been digging into how they compare to each other. That rabbit hole turned out to be a lot deeper than I expected.

So I am mostly here to read and learn from people who actually run tanks. Thanks for having me.

 

[revhtree Verified Admin]

Welcome to your new home for saltwater reef aquarium resources and fun! Welcome to the family! :D

 

[FrugalReeferJon]

 

[kevgib67]

Welcome Thomas, glad you are here!

 

[EnterName]

Welcome to Reef2Reef!

The target ranges are mostly decided by the laboratories themselves because there is no good data available for most parameters. We know their levels in natural coral reefs reasonably well, but they might change throughout the day and over the year. Additionally we found out that certain parameters are better kept above or below natural levels. Alkalinity (not a trace element but still a very important measure) for example is usually kept above natural levels. Most people do the same with nitrate and phosphate as well. For a while people tried to mimic the very low nutrient levels of the ocean but found that this could potentially trigger the growth of dinoflagellates which are really hard to get rid off sometimes. There are also trace elements that might not be required at all as they either have no biological role or are not taken up through the water but through food.

 

[winxp_man]

 

[vetteguy53081]

 

[Peace River]

Welcome to Reef2Reef!!!

 

[keagan]

 

[fishface NJ]

Welcome

 

[JumboShrimp]

Welcome to R2R!

 

[ReefNutsThailand]

Welcome

 

[Fish Fan]

Welcome to Reef2Reef!

 

[Gumbies R Us]

 

[Pomma]

@EnterName thanks, that's really useful, and it lines up with something I ran into.

I'd been collecting the reference ranges ATI, Triton and Fauna Marin publish on their own sites, mostly to see how far apart they are. What surprised me more was what I couldn't find: none of them publishes any number for the uncertainty of their own measurements. Detection limits yes, ATI at least. But nothing about how much a result moves if you run the same sample twice.

Which makes your point land harder than I first read it. If the ranges are largely the labs' own calls because the underlying data isn't there, and there's no published precision either, then a low / normal / high verdict is doing a lot of work with very little behind it.

Have you ever come across a lab publishing an actual repeatability or accreditation figure? I'd like to be wrong about this one.

Also taking your point about parameters deliberately kept off natural levels, alkalinity and nutrients especially. I'd been treating natural seawater as the yardstick for everything, and that's clearly too blunt.

I wrote the whole thing up in the research forum if you're curious.