If you have the kind of water that has little buffering capacity and can easily suffer drastic Ph swings then you have to be even more careful and conscientious about doing that maintenance.
I have used wet drys etc. but these days I use simple equipment. Iam interested in trying is the FBF. But only because from what I have heard they sound simple, effective and small.
What do I use now? Corner box filters as well as homemade ( I found a wholesale source for chemical free open celled foam) and commercially available sponges.
As for water changes? 30% once per week and more on tanks that are overloaded.
I have excellent stable water so that helps but, water changes, water changes, water changes....
Chris
drews at webgate.net