Re: Iron dosing causing hair algae.
I'm pretty confident in my KH readings. I do, at times, double the water sample to increase the accuracy, but haven't found any real errors in the standard reading. It helps that, for KH, we are looking for an abrupt and big color change. Also, the 1.0 PH drop test doesn't require knowing KH anyway, but the PH/KH test still needs PH. Is there a PH meter accurate to +/- 0.05? And, does it cost two arms and both legs? My memory says the cheap PH meters are only accurate to +/- .1 or .2, which really isn't of a lot of help with the 1.0 PH drop test.Tom Barr said:Even with a pH meter, unless the water is RO or tested for all forms of alk, it's difficult to be absolutely sure.
Another common pH problem is stray electrical current from light ballast etc, this can drop pH readings.
Turn the electrical devices on/off to see.
You can use 10mls instead of 5 mls for the KH test kits, this will give you 0.5KH units.
The Lamotte Test kit is accurate to 4ppm of KH. Not bad, add 2x the volume and you extend this to 2-4ppm. You need lab equipment to go further.