Hi, very new here but have been lurking around and with help here, I have been able to get two tanks set up - a 5.5 gallon and a 10 gallon, both planted and each with 1 betta. Substrate in one is gravel, the 10 g has CaribSea Super Naturals. Tanks have been set up for about 6 weeks and both are cycled (ammonia 0, nitrites 0, nitrates 5) testing with API master kit. I will pull the horseshoe out of my butt on how nicely the cycling went I have a Marina i25 submersible in the 5.5 and a Marina 75 Penguin in the 10 g but I have been looking at replacing them both with sponge filters. The current (ha, pun) filters are both baffled within an inch of their lives but I understand the sponge filters can be a nice addition to a betta tank with gentle flow, plus I like the idea of the ease of cleaning. Also, since I have upgraded my lighting for the plants and replaced the original hoods with glass, nothing fits right. I have sponge filters on the way - a corner sponge filter for the 5.5 and the XY dual sponge filter for the 10 g. Am I tempting fate to change them out? What would be a good way to introduce the new filter without disrupting the cycle? I can run both filters at once - there is enough real estate and I don't care how it looks. Thanks in advance for any input.