Hello!!!!!
Good news first - I cleared up the HITH!!! Thank you to everyone who helped!! He pulled through and made a comeback - Not even a sign of damage!!
Bad news, I went on vacation for 2 weeks and come back and my boss had cleaned the tank (used loosely), got a new Eheim filter, and 3 new SMALL fish (we now have 1 new small fish)!
Well, I come in Friday last week and one of the fish had been destroyed! And yesterday another one....Well yesterday the water was cloudy/milky with an oil slick type thing on top - so I did a water change. Today, it was worse!! I did another water change.
When I left here 2 weeks ago the water was PERFECT! The parameters are now:
ph-7.0
ammonia - 3.0!!!!!!!!!
Nitrate - 40
Nitrite - 1.0

The fish are swimming and eating but the Oscar is significantly lighter in color. Im just very protective I guess of the Oscar b/c I have brought him back from near death twice and I am so scared of every little thing. And the freaking numbers are so HIGH even after the water changes! Any expert advice? Thanks in advance!

BTW: I turned the new filter off and turned the old ones back on for now - still cloudy/oily.
ETS: Sorry if Emergency is not appropriate - The levels is what prompted me to do so.

I have no idea why the water would be oily... But those peramiters will get you HITH again... Do lots of water changes to pring them back into check.

No more vacations for you LOL...

So glad he got over the HITH!

LOL - Next time I go on vacation Im taking the fish!!!
What in the world could have made the numbers jump so high in 2 weeks!!! I cleaned it right before I left and he 'cleaned' it while I was out??? Could it be this new filter? I just dont get the oil slick type film on top of the water - I used 2 rolls of paper towels (i read that somewhere) trying to remove the film and it comes right back??? Im so confused!!

The new filter could definitely have caused the water readings... It was sent into a cycle again... And if you have to go through the cycle again yo might as well do it with two filters...

I would check the new filter, just to make sure the media is right... Leave the old filter running and just keep doing water changes till your readings are right!

I've thought of taking my fish on vacation too! lol

He is Beautiful... That is really milky... But it also co insides with a cycle... If your Boss cleaned the tank, add a new filter and shut off the old filter, you will have to do the entire cycle process again... Make sure you feed sparingly.. How big is he again?

turning off the existing filter could have compromise good bacteria
colony and cause bacteria bloom. becoming oily could come from the foods
or from the lubricant of the new filter pumps. eitherway, it needs water
change to play safe.

I am wondering if the new filter is a canister type, They have a petrloeum product on the big "O" ring when you buy them new, at least mine did, and it seemed to be a considerable amount on mine. But I didn't have any oil slick problems. Maybe the way they lubricated the ring on your filter caused the oily slick. But I am with Nicki I think your tank is cycling again. The oil slick is the weird part.

Sheesh I guess I should have read the whole thread first. Sheesh Paul said the same thing I did. Sorry

hey Sam, there nothing to be sorry about... we are
a million miles away and so happen that we have the same
line of thinking. posting at the same time with same
opinion confirm the possibility of it.

You know it ole buddy. LOL Good evening Paul

i found once that a declorinator i used left an oily slick on the top of my water once. i think it was aqua something or another.