Flowering Cactus

I've had this Christmas cactus for many years now and finally...FINALLY it has actually flowered! Prior, it'd been quite the tease by producing many buds that would always drop off before anything came of it. I'm not exactly sure what changed, but if I would guess that it had to do with what I started to feed it. I usually watered it with plain water or a cactus fertilizer. This year, I got some fish for a 20 gallon tank. I heard that the nitrates in the fish water is great for watering plants and so I did....ONCE and suddenly, I had buds. Not only that, they actually opened! All of the buds!!! I'm definitely saving all that fish water to water anything and everything!!