Pond Boss Forums GENERAL QUESTIONS Water chemistry Fastest way to change PH

I'm thinking about trying some alum in my pond to clear up a recent muddy water problem I have because of my pond expansion project. The water is full of clay particles so visibility is way down and fish won't feed. I understand that if alum is to work well it needs a neutral to high PH. My PH is around 6.0 and my alkalinity is about 40. What's the quickest and/or cheapest way to increase PH without killing the fish. Also, any wisdom on using the alum? I've read what I can find on this forum about this subject and I'm having trouble putting 2 and 2 together.