Fish - Change In Environment - "quieter" Than Usual

I did the usual water change regime this morning. The catappa leaves were due to be replaced and, after boiling the new ones to soften them, I decided to add the cooled-down, tannin-stained water along with the dechlorinated water into the tank, to give the fish a more authentic environment which I thought they would like. However, they don't seem to be too happy - 7 hours post- water change and the tetras in particular are still crowded together in one location, their tails not yet back to their usual bright red, while the harlequins are much more stationary and schooling more than usual.

The saucepan should have been fine ie no remnants of food or washing-up liquid in it, so I don't think that can be to blame. I'm wondering if the fish will just get used to the darker water in time or whether I ought to do another water change in order to restore some normality for them (or might that stress them further)? Another water change would run the risk of the already-low KH (1.5 from the tap, 3 in the tank with the limestone rock) becoming even lower. The fish were perfectly fine prior to this water change - in fact, I'd just been commenting how great it was that they were all doing so well and that the QT hadn't been in use for more than 6 months since the cories' problems. Thoughts welcome; thanks.

Hello fcmf,

I think I would do the w/c asap. You can always deal with the KH later. Could it be insecticide on the Catappa leaves? Would it be worth checking pH?

                                            Skittler

Thank you both so much for your advice, Skittler and RichardW. I put some dinner in the tank which was completely ignored for the first time ever which made me realise something was indeed very wrong. I then saw Skittler's response and thought that was a wise course of action. Part-way through the water change, I then saw Richard's and realised that that must indeed have been what had happened. Almost as soon as the 30% water change was complete, the fish started to perk up and are swimming around now - very different behaviour from earlier and much more like normal. It seems that indeed they had experienced an overdose earlier. In hindsight, I can't believe I was so daft as to think that I was doing something potentially positive and that it would be without consequence. It's bad enough when fish fall ill for no particular reason but infinitely worse when you realise that it was entirely your own fault and could have been completely prevented.

Thanks again, both - much appreciated!

Any other suggestions - an additional water change later on or anything else, or just leave them be and keep fingers tightly crossed?

[Meanwhile, I feel like I need a chamomile tea - but that seems the wrong choice of drink under the circumstances!]

I've been thinking (which can be quite strenuous!). Whatever the noxious substance was which upset the fish, there is still 70% of it in the tank. Depending on how the fish seem, I would think about another w/c, perhaps tomorrow?

                                         Skittler

Been up since the first sign of daylight, to check on the fish. Thank goodness all seems to be well and normality has resumed. Tetras' tails are back to bright red, and they're chasing one another round the tank and among the leaves, as often happens in the mornings. Harlequins are behaving much more naturally. No tight shoaling around the heater or disturbingly unusual but impressive synchronised swimming displays. Everyone devoured their breakfast, most likely being extra hungry after no dinner last night. Lesson learned!

I'll do a further water change today if I can get the KH and GH of the replacement water to increase from 1 and 2 respectively - I'll keep prodding the limestone rock to help that along.

Thanks again for your help, both.

I agree, brilliant news, happy for you fcmf 

Something newcomers to the hobby should be aware of is that fish are the best indicators that something is not right in the tank. fcmf's fish have just demonstrated that very well, and she knew to take notice of the change in behaviour and to work out what the problem was.