Hi all, I'm new to betta fish here, just got my male (Anderson) about a month ago to keep at work as my cubicle is so sparse. Because it's an office, I had to limit the size and couldn't have anything electric - no pump or light, so I went with a simple 1 gallon glass cube aquarium, with some natural stone gravel. I planted some Aponogeton ulvaceus bulbs, which have grown quite nicely.
Now, on to my question! Because it's an office, I'm limited in how I can change the water. Because of the plants, I have been hesitant to just tip the tank over and drain it completely, because I don't want them to get crushed by the gravel. I have been scooping the water out, till there is just a little left, then filling it back up, using bottled spring water. Because its bottled spring water, do I still need to use a declorineator? Also, is it necessary to clean out the gravel? Thanks for all your help!!