I would just do it but thought I would see what the experts had to say. I have a friend I help with their tank (disabled and cant do own water changes and stuff). His tank has 2 walmart brand HOB filters one big one (two cartridges) and one small one (one cartridge). I dont think the filters are working like they should despite cleanings, one makes a noise ( I think motor going out) and other doesnt move much water. Yes Ive taken them apart and cleaned the impellars and all.
My wife and I want to buy them a new Aqua Clear 70 for their tank as our LFS has a great deal on them right now. His are cheap filters and I really dont want to just replace the motor.
If I remove the larger filter (its making all the noise) and replace it with the new one will their be any problem with the tank "min-cycling" from the reduced amount of bacteria going through the filters?
Anything I should do like soak the media in his tank for a few days first, or leave the media from old filter sitting inside the tank?
Any advice would be good as he has some really beautiful guppies in his tank that have taken him alot of years to develop and I dont want to see them harmed.