Hi guys. just thought id chuck some info in regarding Po4 testing etc.
Not sure if you get it over the pond but our most common kit over here is the Merc Kit which measures from 0.14ppm down to around 0.008ppm
One important thing to remember when testing for phosphate is to have a kit or apperatus that measures accurately within the specific ranges that we are targeting in tanks.
Basically your ideal target range is from 0.03ppm (the upper recomended acceptable limit prior to calcification inhibition in stoney corals) down to around 0.005ppm (below this and its believed you may start to get issues with deprivation)
The crucial bit is to undestand the meaning of all those 'noughts'...ie that 0.3ppm is 10 times the concentration of 0.03ppm. and 0.003 is 1/10th the concentration of 0.03ppm, and 1/100th of 0.3ppm...It makes a huge difference between success and failure where you have an extra nought....0.03ppm (acceptable) 0.3ppm (bad...actually 10 times as bad)
The last important thing, is to know the error factor of the kit ie its +/- factor of accuracy.
If you look at the spec sheet for the hanna meter shown. It has a resolution of 0.00 with a +/- factor of 4% or up to 0.04ppm
So basically, Even if you are getting a reading of 0.00 on that meter it 'can' mean anything up to 0.04ppm which is already above the 'maximum' recomended.
This is probably why theres such a large difference in price between lab grade kits and apperatus, compared to your cheaper and older test kits which simply dont measure into the ranges that we realy need. Basically a kit or tester that reads from 0.03ppm 'upwards' is only any good for telling you that your already 'over' the recommended levels. beyond that, its pretty useless if you want any kind of indepth view of whats going on inside your tank or run any kind of long term projected trends. Ie watching your readings going up from 0.02ppm by say 0.002ppm increments over several weeks to ascertain water or media change schedules that prevent hitting that 0.03ppm threashold.
ok its a bit anal i know, but its surprising what you can learn about your system and how it performs if you take time to look deeply and accurately enough.
Regards
