what if i take water from a tank where the plecos are breeding and put it in a tank where i have another pair tht i want to breed. will this spark it?

it has been suggest in other place so why not give it a try dude.....

Do you want to try this because you think there may be a chemical stimulant in the water

As far as I know there is none and it would probably less of a trigger than a normal cool water change, but you could try it anyway so long as there is no risk of any cross contamination.

There are some breeders who believe having livebearers like Endlers or Guppies in the same tank can trigger a spawn due to chemicals that they release when mating but I'm not sure if there is any scientific proof of it.

what is a good ph for breeding