Last year december after Christmas, I bought 2 bettas, one light blue (Tommy), another sapphire blue (Dolly). I kept them in soil-based, natural planted tanks. They have lived well, eat well and swim well in the past 3 months.
In the middle of march, Tommy passed away. It is only natural for breeder to ponder upon the cause for the death of their beloved fish. He had fin melt and color loss, no rotting signs. I didn't think too much. Old age. As Tommy had been acting slow since I bought him and he was not the hyper type typical of betta splendens. Maybe he died of illness because he was moved to the hospital tank twice in just 3 months. Recovered and got sick again, and then recovered.
One hour ago, 10th of April, Dolly left, after 4 days on medication. He, like Tommy, had been kept in the NPT tank, before moved to hospital tank for fin shortening. On day 1 of medication before he passed away, his eyes were tad cloudy and body covered with thin white film. Still active and swimming. Day 2, eyes became less cloudy and white film reduced, at the same time his sapphire blue body began to turn dull, gills seemed inflamed, body slime peeled off. Less active. Day 3, eyes became clearer again, the rest were neither any better nor worse. Lethargic. Day 4, appearance remained as the day before. More lethargic. I could hardly do anything as he is already on medication.
This is the first time I ever keep fish. There are so much, so overwhelming, stuff I have learned during these over 3 months of fish keeping. For those who wish to keep their fish in a soil-based planted tank. I'd advise you to use a suitable soil substrate. You might want to check if the soil is too nutrient-loaded. According to a friend here, gardening soil might gradually release nutrients into the water and make the water nutrient-overloaded. Make sure the nutrients are properly absorbed by enough plants and the right kinds of plants.
This is my lesson learnt. I greatly suspect that, for a long period of time, I was totally ignorant of the water bio-chemistry as I do water change every week for my soil-based NPT tank. And the water was always crystal clear! But after a few weeks I set up the tank, the plants overgrew and I trimmed them. After another week, some plants start to die off, with some new shoots growing. A layer of green mosses grew on the wall. (One friend told me the tank water is too nutrient-overloaded, and it led to the growth of harmful bacteria populaton) Apparently, the system in my NPT tank crashed and led to my fish's illness. Tommy might die of age, but Dolly's is not the case I believe.
Yes I am sad for the death of my 2 bettas after 3 full months being with them. And I regret my ignorance. I have been educated by my 2 awesome bettas. Next time, when I am ready to pick any betta again, I know exactly what I would do. This is memorial and I am sad. But I want to say my bettas were living examples of a fighter, teacher and dreamer. Rest in peace.