How to slow filter flow?

[Esmerelda]

Ever since I cleaned my betta's filter. I wrung out the sponge, but not too much so the filter media isn't stripped of all the beneficial bacteria. Sometimes since then, I've noticed that the flow of water is way too high. It will shoot out and blow my fish around. Other times it's just fine. This filter has given me NO trouble before. I actually just bought it to replace an old one I had. The old one broke because I had it for a very long time. If possible, I'd prefer not to replace it. I'm in the process of replacing my third finicky heater, so a new filter would just be a lot right now. Like I said, it's been fine for a long time.
I don't want to unplug the filter, because then there won't be enough oxygen flow. Any tips? I appreciate you all so much. Thank you for your time

 

[Noroomforshoe]

What kind of filter is it?
If it is a hang on the back, you can use wire, thread, string or rubber bands to attach a chemical free spong or felt or a cut filter cartridg in front of the filter outflow. Or you can try attaching a cut up water bottle, look up filter baffle on you tube.

Or you may want to switch to a sponge filter.

 

[RayClem]

One way you can reduce flow is to add a prefilter sponge to the intake tube of your filter. This works with both HOB and canister filters. Purchase a filter that has a hole slightly smaller than your intake.

If you want to reduce excessive currents without reducing flow, you can always make a flow diffuser from a plastic water bottle or the plastic mesh "canvas" used for needlepoint. The mesh is available in various mesh sizes at most craft stores.

 

[Esmerelda]

I also took my filter apart when I cleaned it. I wasn't sure how to put it back together. After trial and error, it started flowing again. Maybe I messed something up.