kjb, I did 2 water changes, but it did cross my mind that it could be two different meds.
tttnjfttt, the temp has did a constant 24c. As for my girlfriend, she only touches my tank when asked, she has her own to play with. LOL
I'm now recovering from a tank strip down, over 8 hours of it. The fish are back in and every thing is OK(fingers crossed). I'm expecting a mini cycle after using new water, even with using two buckets of old water from my girlfriends tank. Thankfully the tank is looking good as new, or should that be good as old. Anyway, it gave me a chance to change the substrate to gravel with laterite, and install a new background.
As for the cause, it possibly was my fault some where along the line. I still don't know why though.
Thanks again for your advice, I great having a friendly "voice" to help!