OK, my fish-loving girlfriend has gone on a university trip for four days and put me in charge of feeding her fish. The main tank is FOWLR, and houses a couple of snails and a mandarinfish. All good there.
The QT is approximately 60 litres, and is currently housing a bicolour angel and a neon wrasse. I was left with instructions on how to feed it and a rough schedule of when to waterchange (half every two days). Using a mixture of pellets (a very small amount covering the tip of my finger, think a circle 4mm in diameter), mysis (a small squirt) and algae, I fed them at lunch. About an hour later, I scooped out most of the visible food left in the QT. I did the same at dinner time.
Come 11pm, it is bedtime for the fish so I cover up the QT with towels. Then I start stressing about the water. Did I need to change it today? Can it wait? I decided no, and tested the ammonia with the helpfully unreliable testing kit she possesses. She uses it more as an indication of ammonia rather than getting the exact amount as it is not reliable. I checked it, and it seemed to be quite high. Freaking, I did about a 1/3 water change, tested again, no difference, so I did another 1/3rd water change. I tested again, saw it hadn't changed, got frustrated at the testing kit, so I covered it back up and turned the room's lights off.
I'm really just paranoid about killing my girlfriend's new fish while she is away. The ammonia test kit is unreliable, and I've done two 1/3rd water changes approximately. Is the best thing just for me to leave it well alone until I feed them again? I feel like I've done what I should have in the circumstance, although my experience is mainly gleaned from watching my girlfriend. I'm also worried that my water changes and testing might have considerably stressed the fish, or maybe I didn't get enough ammonia out...
Maybe I just need some affirmation, but a bit of expert advice wouldn't go astray. Sorry for sounding terribly green at this, the last time I had to look after her fish she had other ones in the established tank and so I just needed to worry about feeding. Any comments are welcome.