RO System

Exciting development! Good luck and keep us posted on how the instalment goes, etc.
 

Hi @fishtales

Thanks for the TDS readings. I would suggest that the figure of 742 ppm doesn't quite tally with your GH and KH measurements. Based on these measurements, I would have estimated a TDS reading of 680 ppm. I believe you use the API GH and KH test kits - is that right? My experience with these two kits is that they can be trusted.

Hanna make some good water test instruments. My electronic thermometer is one of their products as is my conductivity meter. TDS meters are actually conductivity meters that convert the conductivity measurement into a TDS reading. I think some meters can give both conductivity and TDS readings. Best to stick with the devil you know.

JPC

Hi @fishtales

Things have gone awfully quiet. How are you getting on? In the meantime...

KH - usually known as carbonate hardness but is more accurately known as alkalinity. KH is a measure of the water's ability to resist pH changes - usually, pH reduction. Many processes in an aquarium have the tendency to lower pH. One such example is biological filtration. Thus, KH acts as a pH stabilizer (buffer). If KH is zero, then the pH could fall to a level that would potentially harm fish and other tank inhabitants. And that includes the nitrifying bacteria whose activity is reduced at pH=6.0 and, at pH=5.5, the bacteria die. This sudden reduction in pH is often known as a 'pH crash'.

I always ensure that KH never falls below 4.0dH. This figure has served me well.

JPC