so, i've had these 2 oscars now for about 2.5 months or so now. all of a sudden i get home today to find the bigger one acting 'depressed'. it was laying on the bottom of the tank leaned up against the side of one of the decorations and while watching it, noticed that it is randomly shaking all over. it will get up off the bottom every now and then and swim around, but inevitably it goes back to the same place and does the same thing, about every 20 minutes or so... can anyone help? as far as i know, the water is right, just had it tested 2 days ago-ish. by the way, the 2 are in a 72 gal tank, and they are between 4.5-5 inches long. the other fish in the tank include 3 pictus catfish, 1 peacock eel, and a blue crawfish which just looks cool...

before asking for water parameters, i sugest you view this thread first.
is the shivering looks like this?
www.oscarfishlover.com/oscar-fish-advice...-suffering-or-inpain

no, nowhere near that drastic, in fact, it's kind of a slight up and down shiver that only lasts maybe a second or 2. i'll try to get it on camera tomorrow, would have been a good idea for me to do so before i posted i guess.

You need to get a Liquid water test kit and post your water readings. Or have your water checked by the LFS, and post EXACT results!

Is a fish breathing heavily at all? Also, is it eating? finally, all the other fish are behaving normally?

@ OFL- no, it's not breathing heavily and all fish including it are eating without a problem, and the rest are behaving just like they always have.

@nicki- ph is 7.5, ammonia is a bit high, at 3 ppm, nitrate is .3 ppm.

just removed a dying plant, who knows exactly what happened to it, just doesn't look too hot. maybe that could be the cause of the high ammonia. not more than a week ago the ammonia was at 0. i don't think i feed too much, i mean there is literally no leftover food ever between the 2 oscars and the catfish.

What about your reading for Nitrite?

Your Ammonia reading is HIGH! Have you cleaned your filter recently? And if so How did you clean it?

You need to start with a 30% water change a day until your Ammonia gets back down to 0.

I have a under tank filter, not canister, and I change it every water change as I assume I should, I've left it in there before but it seemed to just get clogged up and had to change it anyways.. I have been doing a water change of about 20 gal evey other weekend is there some other way to get the ammonia level down? I mean It hasn't dropped since I got the tank which makes me think there may be something else I am unaware of that's raising the ammonia..

UGF Are designed to hold the mess, your ammonia is high because your fish creates too much mess. You need to find a good canister and remove your UGF!

In the mean time, like I said, 30% water change EVERYDAY!

no, not under gravel, under tank, i'm not sure exactly what it's called, but it holds roughly 5-7 gal of water, has a return pump and some bio balls. i've read waaaaayyy too much about ugf's being worthless really to ever consider it.

Ahhh ok, so you have a Sump Filter

ok, The bioballs you RARELY need to clean, you will just need to change the filter floss...

It sounds to me like you are having a mini cycle. You will just have to do the daily water changes until your Beneficial Bacteria can get built up.

The other problem I see is your Sump is not big enough for your tank. Your sump needs to be 1/4 of your tank Volume.

I would still look at getting a big canister, or at the very least, a bigger sump.

yeah, i haven't touched the bio-balls since i put them in really, and that's been 2 months. 1/4 size really? i mean it's the one that i got when i bought the tank. of course, i did buy it from some guy on craigslist so it may not have been completely legit in setup. i have noticed that the system tends to lose roughly a gal of water a day as you can notice it from the sump being low, and occasionally i forget about it and it gets kinda low to the point that the bio balls aren't exactly UNDER the water, though they have water flowing over them. could this create a problem in not letting the bacteria grow, or when it is low do the bacteria die off from not being completely submerged? i've looked for a way to have an auto top off valve or something of the sort, but they appear complicated to install, and since i live in an apt it's gonna be hard for me to get to a water line to connect to.