I put my comet goldfish in a new tank yesterday. The tank is about 150 litres (40 gallon) and I used the Fluval biological enhancer for three days (with the new filter in) to speed up the cycling process. I added gravel, plants and some water from the old tank. He transferred over fine and was happily swimming around until this afternoon when I noticed that he was swimming up and down A LOT. Then I noticed that his body was doing these tiny convulsions and every now and again he does a mad dart around then settles again.
I have a water tester kit and all the readings seem normal. What's going on?? I've worked so hard to get this little fish a good tank setup and thought that this would be his dream home until he gets a pond. I really don't want him to suffer now!!
Sorry to read about this. Do you still have the old filter and its media? If so, and they were in use up until the point that the new filter started being used, there's a slim chance that the existing filter media's beneficial bacteria may be able to be resurrected from what will be a dormant state. Unfortunately, the evidence for the use of biological enhancer type products is still equivocal, whereas continuing use of the previous/established filter media ensures the ongoing presence of beneficial bacteria (but NB, even if you do still have it and can add it into the new filter alongside the new media, it may take a while to re-establish the beneficial bacteria).
Your best course of action under the circumstances is to do daily water changes with dechlorinated water to ensure that ammonia and nitrite stay at 0 and nitrates no higher than 20 ppm above tap water nitrate levels. There are other things which test kits don't test for and which may be present such as stress hormones as a consequence of the move.
Some more plants and decor (ones which he won't get stuck in / damage himself on) may help him feel more secure and less nervous in his new environment too.
Hope that helps. Keep us posted on how he is and we'll see if we can help further if that's needed. Best of luck.
Thank you! I stupidly cleaned everything the same day, thinking all was fine. I came down this morning and he's swimming around but just not his normal self - very nervy and his body jerking at times. He's got lots of plants, which he was happily munching on yesterday (I started to wonder if he poisoned himself!). I did a 25% water change yesterday. Should I do a bigger change today? He's eating and swimming but his movements aren't right and he jumps at the slightest thing. My kit doesn't test for ammonia - is it worth getting one of this today? I have a really good aquatic store just down the road.
I've fed him two peas but I'm reluctant to feed him more at the moment until I'm sure he's right again.