Too Much Light causing stress and ich?

[Protazerg]

I have a 75 gallon thats been set up for like 6 years, and a couple years ago I got a light with 8x 54watt T5 HO's on it. is that too much? I am having issues with any at all new fish in there getting ich, and dieing, but the fish I have in there are doing quiet well. I just have 4 green cromis, 1 flame hawk, 1 lawnmower blenny, and 2 engineer gobies. they all seem to just mind their own thing. but if I add a tang, or a wrasse, or something, the new fish seem to get ich after being fine the first few days. and these fish have even been at the LFS for quite a while doing fine, because he lets me pay for them, and then he keeps them for me for a while to make sure they have no issues before I take them home. I thought since maybe my light was so bright, that the new fish might be getting stressed from it? Is that possible? do you think I can get away with growing corals and bubble anemones in a 75 gal, with a 4 lamp fixture, instead of an 8 bulb one? thanks a bunch

-Matt

 

[b0bab0ey]

Too much light has nothing do with Ich. Stress can lower a fish's immune system and make that fish more susceptible to Ich. Just like stress can lower a human's immune system and make it more likely to contract a virus, such as a cold virus. At the end of the day, Ich is a parasite and that parasite is currently present in your aquarium. Being an aquarium is a closed system, that parasite has no where else to go. It was introduced to your aquarium from a fish you purchased (probably the Tang) and didn't QT beforehand. Your LFS can hold a fish for you for years, but if new fish keep coming and going from the aquarium he's in there's a very good chance one of them will introduce Ich to that aquarium and infect your fish.

Now, what to do: Remove all your fish to a separate QT, and treat with either Cupramine or hyposalinity (see links below). You must also leave your DT fallow (fishless) for 9 weeks to starve out all the remaining Ich parasites. No fish = no host = no food for the parasites = They starve to death.

http://www.reefcentral.com/forums/showthread.php?t=1992196

http://www.reefcentral.com/forums/showthread.php?t=1991470

 

[sandwi54]

as b0bab0ey said, light has absolutely nothing to do with ich. ich is a parasite that needs to be introduced into the aquarium for it to exist, just like lice and fleas on mammals. i take it that you never QT new fish, so there are two possibilities why the new fish keep dying and old fish are ok:

old fish = chromis, hawk, blenny, goby
new fish = tang, wrasse

1. old fish had ich and brought it along with them into the DT. some old fish developed temporary immunity and became resistant to ich. however, they could still be mildly infected in the gills where you couldn't see, and as a result you concluded there's no ich in the system when in fact there still was. when new fish were placed into DT without QT, they had to go through the stress of adapting to a new environment. their immune system weakened as a result, and contracted ich that's already in the system and died. tangs are very susceptible to ich as their slime coat is thinner than that of other fish.

2. you were lucky and none of your old fish came in with ich, so your DT had no ich prior to the new fish. New fish (especially tangs) had ich (albeit minor infections that may not have been visible to the eye) and were introduced into DT without QT. new fish were stressed out by having to adapt to a new environment, so their immune system weakened and they were not able to fend off the massive ich reproduction and attacks, and died as a result.

in either case, your DT has ich now and that is something you need to fix. follow b0bab0ey's direction on treating the existing fish and getting rid of the ich in your system. then proceed on buying new fish and absolutely QT them and treat them before introducing into DT. QT is an absolute must in this hobby.

 

[Protazerg]

I was just thinking that the fish going into an uber bright system was causing the stress, and the fish getting ich cause of the stress. I heard from somewhere, too much brightness can be bad on a fish's eyes, and stress them a great deal

 

[sandwi54]

it is possible for lights too bright to cause stress on the fish, but fish don't "get" ich from stress. ich either exists in a tank or it doesn't. if it doesn't exist, the fish can get stressed all day long and won't be infected with ich.

what stress does to a fish is lowering its immune system, thus making it more susceptible to the ich that's ALREADY in the system, and hence the massive number of white spots on the fish. please read my previous post as I believe that I have explained well enough the presence of ich and when/whether symptoms are visible to eyes.