Mg vs Ph

OK.

The accuracy is the limiting factor of your measurement! Typical error of aquarisitc pH monitors is 0.1 pH unit, although the resolution of the measurement is 0.01. Check your manual! The resolution arises from the attenuation of the current coming from the pH electrode. Therefore, when you see 8.16 you should round it to the nearest fraction with only one decimal - 8.2. How do I know that ?! Well, I use pH meters in lab and even the best ones that are few generations ahead of aquaristic equipment are only reliable up to first decimal place in the fraction! If I were you I would try to repeat the measurement at least 3 times (every 5 min. after the addition of Mg solution, to let the tank equilibrate) and always note down the temperature. pH and temp. are related (this is why your pH monitor has got temperature compensation algorithm)...

Summing up: pH may drop after addition of Mg solution, because of sulfate anions that come with magnesium. However, high levels of dKH compensate this effect, via chemical buffering mechanisms. If your dKH is to low you may observe a significant drop of pH (at least 0.2pH units)! However, remember that pH measurements also contain some error, in most cases +/- 0.1 pH unit. So, before you draw conclusion take this stuff into account!

BTW.

Your tank is truly amazing...! I'm jealous !

Cheers...!

 

understanding the limiting factors of todays technical instruments, the pH probe is always submerged so the temp fluctuation shouldnt be a factor. but the meter still registered a slight decline. the dkH is 15 which is not low, so the Mg with sulfate shouldnt have had an effect on the pH. but there was also a slight decline in pH with the addition of Mg without sulfate.

there are many types of Ca i.e. chloride, hydroxide and so on. there are many types of dKH i.e. carbonate, bicarbonate and so on. there are many types of Mg i.e. malate, sulfate and so on. depending which matrix used would they bond or repel?

there are different delivery types of supplements i.e. liquid, powder, granual that all use different types of the elements above. would a matrix of the different delivery types with the different element types bond or repel others?

thanks for appreciating the tank.

 

Yes. Some of them could form insoluble salts.

Yeah! There are different supplements, but it is up to the user to pick one, check the composition and try to predict some of the side effects of application. I would suggest: try before you buy... It is wise to stick to one or at most two supplements IMO. In this case adding Mg2+ is like cooking; there are several ways of preparing spicy food: chili, pepper, paprika, curry but you pick only one for your dish depending on the final effect you want to achieve...!

Cheers !