Apologies for being off topic.
My tank pH swings from 6.6 to 7.6 in under 10 minutes every week when I do a water change. I've been doing this for about more then 5 years now. I've yet to see any effect on fishes health. To be clear this is a CO2 injected tank and the waters are identical as far as kH and gH.
The pH (a measurement of the ratio of positively and negatively charged hydrogen ions) is only loosely related to TDS and hardness. To suggest to newbies that measuring pH is a way to avoid osmotic shock seems like a recipe for disaster to me. General hardness and carbonate hardness (significant contributors to TDS) test kits are readily available and quite adequate for this purpose.
but if you have a tank with a pH of say 6.0 and do a 50% water change with hard tap water of a pH of 7.8 or so, your pH will likely go up at almost a full point..which CAN have a detrimental affect, and quickly sometimes.....
My tank pH swings from 6.6 to 7.6 in under 10 minutes every week when I do a water change. I've been doing this for about more then 5 years now. I've yet to see any effect on fishes health. To be clear this is a CO2 injected tank and the waters are identical as far as kH and gH.
a pH test kit.
its much cheaper than a conductivity meter
it is a simple indicator of what you are saying:
that is the increase in TDS and the accompanying osmotic shock (rapid change in osmotic pressure) that causes all the problems.
its easier to use pH as an indicator of what is happening with the TDS increase/decrease from the change....
The pH (a measurement of the ratio of positively and negatively charged hydrogen ions) is only loosely related to TDS and hardness. To suggest to newbies that measuring pH is a way to avoid osmotic shock seems like a recipe for disaster to me. General hardness and carbonate hardness (significant contributors to TDS) test kits are readily available and quite adequate for this purpose.