So, a while back, I posted a thread about my 5 gallon divided tank. I made some homemade rock caves using 100% silicone. I could have sworn that I read somewhere that it was safe. But, after I added 2 betta to it, one got really sick and ended up passing away. I felt horrible. This was about a month ago if I remember correctly. Well, the other betta (Element) was fine, and i took him out of the tank and put him in another for the time being. The only problem I noticed is when he would go for food, it took him a couple tries to get it, like he couldn't tell exactly where it was. He was healthy otherwise. After that, I cleaned everything in the tank, as I could feel the slime from the silicone breaking down. I painstakingly picked all of it off my rock caves, washed the rocks, then remade them with aquarium sealant. I cleaned the plastic plants and threw the gravel away as I couldn't think of a way to clean the silicone off of that.
I added everything back in and let it sit for a few days to see if any slime came back from any silicon I missed. VERY little happened again, so I cleaned it off and filled it again. I then added Element again. He had been in there for 3 weeks (maybe a month) with no problems. No behavior, color or health change. Still doing the food thing, but nothing else. I came back from a weekend at home and he passed away.
My question is, I'm not sure if there's still silicone in there that got to him, or if it was from his time in the tank when the silicone was in there. I'm afraid to put another fish in there now. There is no slime anymore. But also on my way back up, I stopped at petco and picked up a gorgeous blue and white CT for the other half, as Element was doing fine. I temporarily put the new one in a 1 gallon bowl I had laying around. (It's still warm enough that the water is staying at the right temperature). I'm so afraid that this tank is going to kill another fish.
Other specs you might want to know-
5 gallon divided tank- uncycled. 100% weekly water change (I know i'm crazy) Divided with plexiglass, 50 watt heater. plastic plants, rock caves. Conditioned with Aquasafe. A snail as a tankmate on the other side of the divider. (temporary, was gonna move him when I got another fish)