Thanks to everyone for their quick input.

Let me clarify a few things:

1. I misstated my pH. It was OVER 8.0

2. Yes the pond got VERY warm for several days. I don't have a thermometer
but I commented to my wife that the water felt like bath water.

3. I've got a Cyprio Bioforce 250UVC filter, pondmaster 1000 prefilter. I
do have a filter that shoots to a water bell as well as circulates the
water.

4. I have lilies in my pond (3 pots of them). They were flourishing. But
now seem to be holding pace and possibly dying off. The larger pads are
yellowing and the smaller ones are turning brown around the edges.

It wouldn't surprise me that my ponds are too small. I suspected there was
a problem when the temperature shot up so quick. Unfortunately there isn't
any real shade for the pond. Its in full sun from the dawn till dusk.

So what is the solution? A larger, and deeper pond? Maybe expand it to 750
to 1000gal range? What kind of filtration is easy on the pocket book. I'm
going to back to school and that takes up a large portion of my budget
anymore.