More airation may help, warmer water has less disolved o2. It was your statement abut your serving fishe's rapid breathing that makes me think it may help. I don't think it is the major factor but it can only help, espicaily at night, when the plants are using it up.

Thank you. I must admit it took up my weekends with cleaning tanks. So what would you recomend to a person on a budget. I remember one of the guys at my fish store (now out of bussiness) recomending a biowheel. I will use the net to find out more about them. Still not sold on sand. I would get a wet ...

Thank you for the info. Your discus are amazing! I should have been more specific I still want to use an undergravel filter in my tank that will include cory cats among other fish. I know sand is the favorite substrate, but I love the gravel and have had cories on it before without nose trouble. I ...

I was wondering if anyone in the USA knows a good sorce for small rounded gravel.