what is a good ph for breeding BNs? the ph in the bigger tank i was gonna put them in is 8.0. is that to high? and if it is how do i lower it?

this has been covered a lot.

Have a read of curbys breeding post

http://www.bristlenoseworld.com/t1320-breeding-the-bristlenose-pleco

this goes through the basics.

or my book has about half a page about pH and how to adjust it.

tho, in short, too high. Bristlenose are amazonian and they need soft acidic water. i suspect that your water is both high in pH and hardness. Add some wood to soften it and make it more acidic

try indian almond leaves or blackwater tonic that also can lower your ph also or aldercones i use them in my hypan tank hope this helps