A plea to Randy Holmes Farley

Dnahacker · Feb 13, 2015

Hi Randy

I have been a big fan of your contribution to the hobby for many years, however can i please ask something of you, as a fellow scientist.

Can we have things in a standardised format moles etc as well as the obscure units of measurement you prescribe

Whilst i appreciate you live in the USA your audience is global, not all of us have access to the domestic products you suggest are suited to reef chemistry.. a great case in point is your DIY 2 part additive plus mg. i cannot buy dow flake in the UK or many of the other products you highlight.. but i can get BP and analar grad chemicals.

You give measurements in cups (i had to google) as i understand a cup is 8 fl oz which is around 238 ml? does dow flake have the same density as calcium chloride ? is dow flake a hexahydrate? dihydrate? anhydrous?

Molarity would be a massive help..

Thanks

Randy Holmes-Farley · Feb 13, 2015

I hardly consider the units I use to be obscure. We who give info to hobbyists need to recognize what they know and what they don't know, and your average hobbyist knows cups and grams rather than moles.

That said, I recognize that different people prefer different units.

I fought for years to use scientific terms for things like alkalinity (in meq/L), but the kit makers keep most alk kits in dKH (an utterly ridiculous unit) and so I've largely given up on that.

You will find that in my DIY two part recipe, I give the recipe in grams, except the magnesium part which is based on a 64 ounce package, which is how they come in the US. I'm sorry, but if you want that recipe in grams, you'll have to multiply by 28.35 grams per ounce. I also give the concentrations of every part of the two part in meq/l or ppm (mg/l) so there is no ultimate ambiguity of what to make.

If you want molar recipes, I'd suggest using the ppm and meq/l concentrations to guide you. Starting with the ppm units, just divide by the molecular weight of calcium or magnesium to get mM concentrations.

http://www.reefkeeping.com/issues/2006-02/rhf/

Dnahacker · Feb 13, 2015

Thanks... i think that the recipies have been reproduces so many time bits get lost ... the version i read just had too much missing to make sense of it...