Peculiar acting fantails

[KJoFan]

I have 2 fantails in a 30 gallon tank I've had for several months now. They've always acted fine, eager to eat when it's time (and when it's not) and whatnot. The past day or so however they seem to be nervous or scared acting or something. If you walk by the tank (it's in a very low traffic area as it is) they don't come up to the front looking for food like normal, but dart off and hide in a back corner. I was trying to observe them last night and one would seem alright then suddenly dart around the tank, then just stop and hang around. The other tends to sit on the bottom and hide. They both came out and ate though when they were fed. I promptly checked the water parameters: Ammonia 0, Nitrite 0, Nitrate 10, pH 8.2 (this is normal, as it is out of the tap). I gave them about a 20% water change and let them be for a bit and went to research. The light over the tank is kind of sketchy so I didn't know if it could be some kind of electrical current getting in there, so I switched that out to one I know is fine. Then read about heavy metal poisoning. There are colored glass pieces in the tank so I wondered if those might be causing problems somehow. I scooped them all out and did a 50% water change and left them over night. They don't seem to be acting any better or worse today. Physically, they appear perfectly fine, not clamped or anything. Anyone have any ideas what might be going on?

[pl*co]

Interesting. I think you've done what you can to perk them up with the first, smaller water change. Careful though, with your nitrates being low to start, and then with that 20% followed by the 50% water change, you might accidentally send your tank into a new mini cycle.

One thing to try is to leave the light off for a day and just let the room light suffice. Another is to put more items around the tank in various places to provide sanctuary, such as plants, rocks or wood that they can get behind, but that still leave enough swimming room.

Perhaps changing the wattage to a lower one or to a less bright area of the spectrum might help. On the other hand, something may have occurred in the vacinity of the tank when you were not around that spooked them and it may just take a few days for them to calm. Please keep us posted.

[KJoFan]

Thanks for the comments and suggestions, everything is appreciated because this one has me a bit stumped!

I will keep an eye on the water params. I only did the second larger change thinking that if there was some kind of toxin in there, to try to dilute it or remove as much as I could. I did leave the light off all day yesterday and just kind of let them be. Checking on them occasionally. They were generally hanging out together in a back corner. They came out a bit last night and I fed them, they ate well. As they were eating I walked off to do something else and when I came back they swam away and hid again. This morning I checked on them and decided to give them light today. They came out to the front of the tank, probably looking for food. I fed them and they really went after it and never scared off like usual. So I'm not sure if this is an improvement or just an isolated event. Hopefully they're getting over whatever happened.

I'm actually wondering now if I've been underfeeding them. I generally feed Tetra mini sticks, making sure they each get anywhere from 6-9 sticks apiece once a day. Lately I've only been feeding every other day however. I'm not sure if that's underfeeding them or not but I'm going to try to give them a couple smaller feedings per day and see if that helps them perk up.

I will keep you updated. :)

[wataugachicken]

Careful though, with your nitrates being low to start, and then with that 20% followed by the 50% water change, you might accidentally send your tank into a new mini cycle.


Huh?! Mini-cycles are caused by killing your bacterial filtration. Nitrates are the end product of the cycle, you want to take those out. As long as they are done correctly (temp is matched, dechlor is added) you could do 80% changes twice a day without harming your cycle.

Do your fish have hiding places in the tank? As your fish grow, they may be becoming more *aware* of their size in the tank, and their visibility. Strangely enough, giving your fish a bunch of hiding places makes them feel more confident and they will be out MORE, not less, because they sense that they can hide somewhere if they really need to.

[KJoFan]

They seem to be acting a bit more normal today, I can approach the tank without them "running" and hiding. They do have hiding places in the tank but they could probably use some more. I have fake plants in the tank and am planning to add some more. Perhaps that will help as well. I'm just glad they seem to be acting more like themselves.

[pl*co]

Huh?! Mini-cycles are caused by killing your bacterial filtration. Nitrates are the end product of the cycle, you want to take those out. As long as they are done correctly (temp is matched, dechlor is added) you could do 80% changes twice a day without harming your cycle.

If there aren't enough to maintain the bacterial filtration, then you can get a nitrite spike. If his nitrates were 40 or more, then an 80% water change would not be harmful. On a nitrate reading of 10, it would definately be harmful and could kick off a mini-cycle. I have seen it happen on at least two occasions. Now, having said that, I noted after re-reading that the tank has been up for several MONTHS. I thought I read several WEEKS.