I've been searching for answers for hours, so I'm sorry if I've overlooked where the answer to my problem may already be answered. I brought a male betta home a few months ago and he's been thriving with no issues. yesterday, I added a heater, though I didn't turn it on yet, the temp is still mid to high 70s. I also added a fake soft plant that wouldn't snag his fins, since my last live plants died... thought he would like a second place to hide, although loves his cave. also...and I'm sorry, I just didn't know better, I added a light, a blue one, that was too bright. he has never had a light before, and so after some research, I really think it just stressed him out. so away with the light after waking this morning and finding poor Dorty (my 5 y/o named him:)) extremely lethargic. he would not eat his breakfast. several hours later, we come home from school and he is still very, very lethargic...like, I don't know if he's going to make it. but the water is suddenly cloudy. from what I can surmise, the introduction of the light gave rise to a bacterial bloom, or whatever? I don't know, I'm still figuring this all out as I go, so bear with me...so I vacuumed the gravel, removed 1/2 the water, cleaned the sides, checked the ph...ph is good, added some easy balance... I tried to be very gentle and as unintrusive as possible, the poor guy is so stressed. I have not even added water back in yet. what do I do? will he live? he's in a 10 gal filter tank, eats about 3 pellets of food. he is hanging in there, no physical symptoms other that floating on his side and acting mostly dead, but occasionally will right himself and swim a little. stays near the top...which is uncharacteristic of him. please help? thanks