Yes.....
Actually, it will all be diffused before getting to the XP3 via the Reactor. And will be no problem...
Before I got my current power reactor, I used a glass diffuser under the XP3 intake, worked great. No locking up or anything. The XP3 has anti-airlock protection. Plus with such small bubbles anyways, doesn't hurt anything.
And if you look at the path, CO2 bubbles up, and the intake flow goes down. So the bubbles are going against the flow. If you placed it on the output, then the bubbles in the reactor would only flow up and out of the filter output, wouldn't do any good unless you created a zig-zag in the output line so the reactor is in the correct position. Plus to make matters worse, lol, I have an inline heater on the output. lol. So it would go up through the heater, then you would need a U-tube to go back down into the reactor, then another U-tube to go back up again to the filter. A friend has his that way and said it does cause priming problems and he sometimes has to fill the XP3 up before putting the top on it because it doesn't prime properly.
