sudden fear of light

kernal357

Hoping someone can shed some light on this issue. I have had a 29 gal tank set up since the beginning on august. The water parameters are as follows: ammonia 0/nitrite 0/nitrate 10(6 from tap)/pH 7.6/GH 11/KH 5. 3 blackskirt tetras were added 2nd week of september, after initial fishless cycle. since they were the first addition there was no quarientine. shortely after interduction noticed ICH. innitially treated with maracide per instructions, treatment was inneffective and was directed by mardel to use coppersafe. Changed 50% water as instructed and began coppersafe. Ich cleared up in 5 days, maintained 1.5-2 PPM for total 21 days before discontinuing treatment of new water used for partial water changes. 35%-40% water changes are performed weekly. All 3 fish recovered well, regained appatite, and seemed to be dooing well, one took about a week longer then the others to regain energy and appatite. All was well for a couple weeks when 5 nights ago all 3 were swimming under the 36 watts of actinic blue/10000K light that has been on a 12 hour cycle since the tank was first set up, before I had any fish. I was sitting on my couch enjoying my fish, and eating a snack, I looked up at the tank between bites of pie and noticed that the fish were suddenly huddled
strangely close to the bottom against the front glass looking very stressed. I stood up to take a better look and they started darting all over the tank, and eventually all took cover in a ditch behind a dense clump of plastic plants. They were completely shocked, twitching and on highg alert. a few minutes later the lights were due to shut off, and afterwords the fish relaxed and resumed normal activity. the next morning they were fine before the tank lights went on. no flashing, no twitching, fins erect, playful with each other, no spots or anything abnormal. Then the lights went on and they freeked out, same as the night before. I tried to leave them alone thinking they would relax after a while, when i returned they were acting the same as when I left 5 hours before. I shut off the light and within 10 minutes they were fine. Now it has been 5 days and they are still completely shocked by any amount of light besides ambient room lighting. the room is well lit by the time the tank light goes on in the morning, I have tried a different light above the tank(mutch dimmer) with the same results. I tried to partially shade the tank with some opaque material under the light, same results. but while the tank light is off they seem very happy. My ph is a little high but it has been stable since setup. I would like to resume stockng, but not until i understand whats up with these guys. seems strange that they would change behavior so abruptly? ayone have any ideas. btw there are rocks, and plants to hide in.

1077

Does sound odd. Have you tried some floating plants? Any way to tell if fish remain skittish for the duration the lights are on during the day, or is it only when person or persons enter the room? Any chance of photo of the tank?
I once had a group of Dicus that were pretty much alone for the day while I was at work, but upon my entering the room after work they would scury for the cover of driftwood. After twenty or thirty minutes, they would begin to venture out. they also showed a marked dislike of the light over the tank. I purchased some artificial bamboo grass and let it float on the surface and it seemed to give them a sense of security.

SueK

Any change? My rainbows seem to go through fear periods that sound similar to yours since I upgraded my tank size. It's bizarre.

kernal357

it is now 2 weeks since this problem started. after my last post i left the light off for a couple days, then resumed an 11 hour cycle. slowly, a little more each day they are becoming more comfterable with the light on. with the light off they still seem perfectly fine. there are no signs of illness other then the stress from the light, wich at this point doesnt seem nearly as extreme as last week, and all 3 fish are will now feed with the light on. at this point there have been 4-50% water changes, and 2 fresh carbon filters since the medication. i plan to continue watching then closely through the weekend and perhaps next week i will add 2 more of them to finish out their group. i still have no idea what happened to change their behavior so much so quickly. i suspect that it was the copper medication, however i have not found any one else with similer experience. the idea was brought up that something may have spooked them, but the room was quiet, and nothing around their tank had changed. it was kinda dark outside of the tank, and i geuss a mouse could have been harassing them without me knowing, seems unlikely but?...anyhow they seem much better so hopefully in a few more days they get a couple more friends and will be comfterable again. let me know if you have any ideas what may have happened.

Twistersmom

Hello and welcome to the forum!

Most fish, feel more comfortable in groups. Even single fish can find comfort in differ fish. I wonder, being a small group, if they do not feel more exposed/threatened under the lights. If so, maybe adding more fish will fix the problem. Not sure, just an idea.