Originally Posted by kien (Post 925720)

I use an app that came with my iPhone. It's call "Notes". Works great!

Originally Posted by mike31154 (Post 925831)

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.

Originally Posted by mikellini (Post 925840)

You should really change your carbon block more often, most of them are rated for 20k gallons at 50% efficiency or so, which means that by that time, they are letting 50% of what they should be stopping through. Plus that rating is for continuous operation, so if it sits for some time it will reduce the number somewhat. Plus there's clogging of the micron filter before the block (will happen to some degree even with a sediment filter of equal micron size before it), bacterial growth etc. And it's a 9 dollar part.

BRS has a great series of videos on carbon blocks and rodi systems, a true wealth of information. Myself, I change my sediment filter when water pressure drops from 60 psi to 50 psi, and the carbon filter every second time I change the sediment filter. Probably works out to every 1000 gallons for the sediment, and 2000 for the carbon

Originally Posted by mike31154 (Post 925841)

I thought the main purpose of the carbon block was to protect the RO membrane from chlorine. I have a swimming pool test kit for chlorine that I used before changing the carbon last time & it still showed negative. I didn't wait until exactly 20,000 gallons on the last one, but close. I still use RO water from the system at 1 TDS for drinking etc. with no health issues that I'm aware of. I realize the filter is not that costly, but still like to get the most out of the thing before relinquishing it to the landfill. Besides, the water coming through my tap is supposedly fit for human consumption. A bunch of videos from a vendor are unlikely to make me change my errant ways! Folks are free to change them as often as they see fit, I'm merely documenting my experience. YMMV. And that's where my trusty spreadsheet comes in handy. I don't have a smart phone or iphone, so it's what I do.

Originally Posted by mikellini (Post 925853)

What water were you testing with the script? That is a good way to test if your carbon blocks, as long as you're testing the waste water and not water that has gone through the membrane. You should still check out those videos, great info