Hello there! I have had a Marineland Eclipse Hex 5 for some time now and it's a really great tank! Mine was set up and running but empty and a friend came over with a small 2 inch Ryukin goldfish that someone got her kids. Well she didn't want to deal it so she offered the little guy to me or she was going to throw him in a local pond. I love goldfish so I decided to take him, however I am well aware that a 5 gallon is very far from the best thing to accomodate a goldfish but it's all I have available until February when I set up my 75 gallon. I am doing 50% water changes every day/every other day while he is in this dinky set up.
Because this tank is so small I know I need to double if not triple the filter capacity. I got a small Marina i25 filter which seemed awesome until I realized that because it is an internal filter and the motor sits in the water, it is heating my tank to 78 degrees. Right now I shut the internal filter off until I get more info from you kind folks. Is 78 degrees acceptable for a few months? If not, has anyone ever modified the Eclipse Hex 5 to accomodate a HOB filter? The other thing I'm contemplating is getting a Fluval internal filter but I am worried it will heat the water just the same. I have an airstone in there with a small airpump... should I amp up my air also? I want this little guy to have the best chance at making it to the bigger tank.
Also, in order to keep the tank as clean as possible I am contemplating removing the gravel and replacing it with glass marbles. I feel the gravel harbors ammonia and makes it more difficult to clean. I realize that I am removing something for bacteria to colonize in, but should it matter since my tank is so small and can't really get its nitrogen cycle on point anyway? p.s. before adding Rod (my goldfish) both filters were established in cycled tanks. If you think I should remove the gravel, should I just do it all at once? Or do a little at a time?
Any thoughts on all of this would be greatly appreciated. I absolutely LOVE goldfish and I would love to see Rod reach a big size. Once I can move him to the bigger tank I will get him a brother (Todd)... can you tell I'm excited?