Neocaridina 10g Water Change

My nitrates have hit about 20ppm in my planted shrimp tank and I'm wanting to do my first water change. I might be able to delay it slightly as I topped off the water just now with a gallon of distilled water which should hypothetically dilute the nitrates a bit but that's only delaying the inevitable.
What is the best way to suck up old water and introduce new water, without disturbing the tank too much? Is there a drip water changer available or anything? I have a siphon and motor I use for my 29 gallon but that'd be WAY too strong. Any advice?