[mike31154]

I mainly keep track of water changes & RODI system throughput. I don't like changing filters on a calendar basis, since that has nothing to do with how clogged they get. It's all about how much water you've sent through it and what the TDS out of the RO membrane is. Also, it's good to know when you're getting close to the 20,000 gallon mark through your carbon filter, if it's rated for that, rather than changing at an arbitrary 6 month interval. I've found the less I mess with the RODI, the better it works. Change the sediment filters regularly, but I'm still on the original 75 gpd membrane and only the second carbon block in over 5 years.

Although my spreadsheet has a page for all the chemical parameters, I don't typically check those very often, unless the tank "doesn't look right". But since I've gone to the trouble of maintaining a spreadsheet, it might as well be able to track that stuff. I don't print any of the info to put in a binder. Don't see the need when I can see it all on the 'puter.