Having bred Oscars on a regular basis i can say that they really arent that bothered about the ph so long as its not extreme. Anywhere form ph 6.5 to 7.5 is fine. What Oscars really need are the right conditions.In the wild Oscars spawn in the rainy season, this is because their is an abundance of insect life that is washed into the Amazon river as the rains flood the forest.When the rain pours down it also cools the water and this acts as another trigger. Oscars will spawn in a tank that has good water quality brought about by frequent water changes. Feed Oscars continually for a coouple of weekjs with live food, worms, meal worms and river shrimps and when you do your water change add cool water so that it gradually lowers the temperature by around 4 degrees f. This should encourage your Oscars to spawn. In the wild the ph is lower around the 6.-6.5 nut i found trying to replicate this is such hard work especially in the hard water in my area. To be honest when i changed water i would lower the water level by 4-5 inches i have stuck a hose pipe connected straight to my tap and filled it up with water directly. I have also used rainwater and this is excellent so long as the rainwater isnt contaminated. to decontaminate my rainwater i used carbon. I cut the bottom off a coke bottle and made two holes one on either side and put some string through so that i could hang it under the down pipe. I put a small piece of open pore sponge in first then filled the bottle up with carbon and topped it off with an inch of filter floss. The floss removed any large particles, the carbon took out any nasties and then the sponge stopped the carbon falling through. I jammed a hosepipe in the end and this directed the water into several water buts linked together. I have even drained some water out and directed the pipe straight into the tank when we have had a downpour, via a hole i drilled in the wall.
good luck with your breeding
