I recently upgraded to a controller and love it - and i sure didn't pay $600-$700 (AUS or USD). Ebay has them for less than $100 (shipped): http://cgi.ebay.com/SMART-SMS122-pH...oryZ3212QQssPageNameZWDVWQQrdZ1QQcmdZViewItemPK1 said:I have a pH controller and I can tell you it doesn't do anything for plant "health", you can have very healthy plants without it. At $600-$700, save your money! I would turn the CO2 off at nigh using your solenoid, don't worry about the pH swing, I have been doing this for a while without any adverse effects.
I took some water quality classes at the Shedd (in Chicago) years ago when I lived and breathed Discus .Tom Barr said:Here is the death blow regarding pH swings being bad for fish(any fish or plants or invert): what happens when you do a large water change every week?