Importance of pH with tetras

Question
I have a 29 gallon rectangular tank, biowheel, powerhead, heater.  I plan to have 10 neon tetras, 10 rummynose tetras, 10 rasboras, and 5 panda cories.  I currently have 6 neons and 5 rasboras.  My tap pH is about 7.8 but when I checked the pH from my tank today, it was about 8.0.  I'm worried that when I add the rummynose, it will be too high for them.  I've had people tell me that they will be okay in that pH range as long as I acclimate them slowly.  My concern is that even though they may do "okay", they will not live as long or have the best quality of life because of the pH. I guess the higher the pH, the harder it is for them to respirate.  I've read about blackwater extract that I can add and I've also just bought two small pieces of driftwood.  The blackwater extract says that I should remove the carbon.  Do you think it's more important to have the correct pH or to have the carbon filter in my tank? Is the carbon going to remove the tannic acid released from the driftwood also?  I'm at a loss on what to do.  I know there are buffers I could use but I don't want to spend the money on artificial chemicals to adjust the pH.

Answer
hello Tania,       For info on the driftwood go to thie link below.

 http://www.petfish.net/kb/entry/194/

That will tell you much more than I could possibly type here about the wood.  
about the other things. I'd cut the number of planned fish to 23 total of the ones mentioned. Do not buy them all at once or you will get an ammonia explosion.  A few fish per week. As the weeks pass, your PH will go down normally. Watch it doesn't get below 6.0. Rarely will the PH go up in an established tank. Your friends are correct. While floating the fish bag in the tank, add a cup of water every 5 minutes for 30 minutes. The fish should be fine. My personal preference if I had to choose which factors are the most important?  Clean water, which means the more charcoal in the filter system the better. Then ammonia level at 000. PH at 6.4, then not overfeeding, temp, gravel vac, nitrites/nitrates.
    1....Cure your driftwood (see site above). If the water gets reddish/brown even after you've done that just do frequent water changes and the Tannic acid will go away. Relax, Tannic will not harm the fish. No, charcoal will not remove the Tannic.
    2....leave the PH as it is. It will go down soon after the fish arrive.
    3....Get more charcoal in the system.
    I rarely use chemicals at all. Instead, I use 3 times as much charcoal as is normal. Unless a sickness appears which rarely happens to me now.