How much with Stratum drop my PH?

[WeehawkenFish]

Hey, I'm seeing a lot of people on forums saying that stratum will "buffer" ph down to the low 6's.  Is this true no matter the water you start with?  I have a well established 29-gallon with flourite substrate that has always tested out to 7.2-7.6 ph.  I'm setting up a 2nd tank (20g) to grow out a female apisto or two.  I'm curious if, when the time comes to move my male, will I be moving him into a dramatically different environment?

I'm not really versed on what "buffer" means exactly, but I would think the two tanks shouldn't be too much of a difference because I'm using the same tap water?  Or will the substrate heavily dictate the ph?

[luka]

I have a 20 gallon currently still going and I used stratum as my substrate. It made my ph go from 7.5 to 7.2, my ph has stayed at 7.2-7.3 for the past few months, I think, and by that i mean i dont know, but i think that after 2 years in MY experience the ph will start to go up as you do water changes and the stratum weakens. Your fish will most likely be fine. Ive taken a family friends guppies, tigerbarbs, corydoras and snails come from their tank with a ph just below 8, they went right into the 20 without issue