Hi 👋,, Iím new to this site. Nice to meet you.
I have two establish 200 litre fish tanks. Well was establish and everything was going so well. Both tanks had loads of fish in and had 0 problems. Anyway a couple of days ago I decided to upgrade my u4 to an external filter. Thought it would help. The pet shop guy showed me the working. I put my media into the new filter and got it set up. Turning out to be a pain to work with! I did buy two filters and had one set up on one of my tanks. Anyway after running it. I noticed some of my fish dying straightaway. So I was panicking! I think the filter set up was set up wrong by the manner factor. The filter was a hydra filtron 1000. The media was at the bottom of the tray. So the water goes down the pipe and up though the media to the pads. Then the pads first and then to the media. I phoned the pet shop and asked if I was doing everything right. They said itís fine! But Iím not to sure on it. Anyway I ended up going back to my u4 filters. Got Fed up with it! I added up putting some stability in. And did a water change. Then added some stress Syme. Anyway I notice more fish starting to die. My Gouramis started to die! I had 4 of them all doing well in the tank. 2 died.. so I put the other two into my other tank. What I didnít do the filter! Left the U4 in. Anyway more fish started to die. So I taken one of the sponges from the other tank with the Gouramis in and replaced it and put it into the tank with the problem. Now my other tank as started having problems and fish started to die in that tank! I did water changes and added API zyme. Thought it may help since it as bacteria! But after looking up. People say the bacteria will kill fish bacteria that is on your media. Is this right? Do I really need to use this stuff? I do use the stress coat for water change. Anyway I have lost about 18 fish all together. Not a happy guy.
... Done a water test and both tanks seem to be fine. Iím just wondering if itís down to bacteria. I just wish I didnít bother with them filters now. Thank you for your help.