I am wondering do you really need to buffer the water in my 20 gallon planted tank? I know all about ph swings but if I am doing weekly h20 changes won't that hold the ph realitivly stable?
And if I do buffer what to buffer with? I just got over an algae bloom and don't want that to happen again. any suggestions are appreciated

:)
It seems this is a very opinionated topic. I bufer my water because of the fish I keep in it (Discus), and because the lower pH really does seem to increase the beauty of everything in the tank. I have kept live plants in my fish tanks for years, with out the right lighting and with out buffering. Everything was fine. But, now that I have started to buffer, OMG!!!! I think the difference is so worth it. My pH is at a 6.6, and the way that I get it is by filtering RO water over peat. I will include a few links.
It does take extra space this way, to prep the water, but it is safer than using chemicals, and more stable. All this for a 30 gallon. IMO, go for it!!!

http://hjem.get2net.dk/Best_of_the_Web/peat%20page.html

http://fp.marksfish.f9.co.uk/diy/peat.htm