Hi, currently I had a disaster in my tank caused by adding salt..by the time I found out the cause, I had lost about 10 fish out of about 24. Now, we've saved all the fish with large water changes and a quarantine tank. To see what happened please see "Marble Hatchets dying all of a sudden!" Anyway, I'm going to show my apologies to my remaining fish for their loss by buying them a canister filter. I don't think I have the money to buy an Eheim which I heard on this forum that it's the best. So I'm probably going with one of the Rena's. My question is, how good are the canisters made by Rena, and for my tank, what size should I get? I have a 50 AC HOB filter on it right now...I had a 30AC that working with it not long ago, but it's not working properly right now. Thank you!