I only have a six foot chain on the Parker 25. Lots of times I anchor in
shallow water, and I don't like the "all chain rode" a 25' chain would
give me.

Unless you're in less than 8 feet of water, you should have some rope out as
well.
Even at a short 3 to 1 scope, in 9 feet of wtaer you'd have 27 feet of rode
deployed...actually more if you follow good practice and take the distance
between the bow roller and the surface into account as well as the depth.