My tap water is opaque brown, 10+ ppm iron, 8+ pH, etc..
That is, without filtration:
I inject chlorine, then hold the water in two 40 gallon retention tanks to precipitate iron, then through a katalox light (gamma Manganese dioxide (MnO2) coated ZEOSORB) to grab iron and regenerated with potassium permanganate, then a tank of calcite and corosex to adjust pH, then a tank of MTM (MANGANESE GREENSAND EQUIVALENT)to grab iron and regenerated also with potassium permanganate, then Centaur catalytic granular activated carbon (doggy doo expensive) to remove chlorine and potassium permanganate bleed through, then a water softener.
Unfortunately, even with all this I have to run my water through reverse osmosis.
If I had ideal water I feel I could eliminate most problems with water changes, but I don't.
So I'm measuring to deal with re-mineralization.
Also, I'm running a moderately high tech tank and trying to find fertilization deficiencies and ideal CO2 levels.
I imagine a time where these problems are solved and testing might only be for confirmation, but personally I'm not there.
Of course, I have run my tank for years without measuring anything and not really worrying about re-mineralization and just fertilizing with a set EI formula, but lately I've been challenging myself to discover why I can't grow some plants and why some plants have problems.
I don't test my tank water. I haven't for many years. I simply change most of the water in my tanks weekly and this guarantees a steady water chemistry. This is the only requirement for a healthy tank. My water isn't significantly different than most other areas of the country, so anyone can just remove and replace most of the water in their tanks too. By following such and aggressive routine, there's no time for pollutants to build up in the water before I remove them by changing out the water.
Bump: Yeah natemcnutty if my wife switched out my Apera and I saw two lines, well, let's not go there, he he.
Tamsin I'm trying to keep a log of TDS to get an understanding of my water from day to day as I move through my weekly EI regimen. It is interesting.
What's your nitrate kit?
Or what nitrate kit does anyone recommend?
Does anyone find nitrates spiking very often or is it just for confirmation?