So I added an undergravel filter with carbon filters to my tank... still have my hanging filter. Today the Oscars seem to have an attitude. They are not swimming around like they normally do. They did come over for feeding but hang at the top of the tank behind the tubes from the new filter. Double checked the water conditions.. all perfect.

Too much filtration? Sounds stupid I know ...

Too much noise?

Do they just have attitudes because I changed something in their tank?

Inquiring minds want to know... and wish they could read those little Oscar minds!

can you give us a little bit more information regarding these underground filter & how you set them up? The first thing I and everyone else will tell you is to remove the carbon, it really is not needed and could actually cause more harm than good in the long run if you leave it in there. Basically, corbon used to remove impurities from the water,it will not actually benefit you if you leave it in there.

Did you turn any filters off when you were adding this new filter?

Is your tank being oxygenated, is the filter causing surface agitation?

Finally, you said your water conditions are perfect, that really doesn't tell us anything, could you please post the results that you got.

Everything but the light was turned off when we added the filter.

I will remove the carbons, I have heard that more than once now!

There is a bubbly current across the top of the water. I think the filter was called a Perfect Flow - picked it up at PetSmart (where the people are not smart!). The tubes are about 1" from the water surface, facing each other. The filter is not the perfect size and had to be "fit" into the tank. We have a bow front 26 gallon tank and there are no bow front filters. The only one that fit was one for a 10 gallon tank. It is set up to one side of the tank with about 6" of no filter on the other side. There is no undergravel in the part where the tank is bowed. I figured it would be better than no filter.

I have only checked the Ph and Amonia levels at home. There is another post on here by me to see exactly what you guys recommend for testing kits. The store tested some other things and said it was all within limits.

Currently my bubbler is not working because the pump can not handle the undergravel filter and the bubbler on the 3 way setup. Even though the store said it should be sufficient "juice" to run the filter and bubbler. The bubbler has only been off for like 12 hours. There are bubbles coming out of the top of the filter tubes though.

Is that what they are after? The air at the top which is why they aren't swimming around like normal?

I don't think you've got enough filtration on your tank,I'm trying to read between the lines and you say you have a 26 gallon tank, but your filter is only good for 10 gallons, is that correct?

We really need to know the ammonia readings, not just you telling us they're okay, the exact readings, as in PPM. You have got two Oscars, correct?

Also, how long did you turn your filter off when you were installing the undergravel filter?, Have you cleaned your filter out in tap water recently?

It said that it fit in a 10gal tank. The box says from 10gal to 30gal tanks. I did have to buy extenders for the tubes though so your probably right.

I have two baby oscars - about 2.5" long each.

The Ph sits at about 7.9 ... can never get it to lower.
The amonia is 0.

The over the tank filter was turned off for about an hour. And I cleaned that filter at the same time.

They are spending their entire day at the top of the tank behind the filter tubes. Either they don't like it or they have attitudes. I know my other oscars which were in a 100 gal tank would get attitudes when I changed things.

OK... I just shut off the undergravel filter and put the bubbler back on. After 5 mins they are swimming around the tank like normal!!!

I hope you don't plan to keep them in that 26gallon tank for very long.

No... they will not be in this tank for long. But at this point they have plenty of room. I am shopping for a tank which will be 100% set up before the fish get moved. I am sure I have a month or two!

I have used UGF's when I first started keeping fish. Personally I think they work fine in tanks under 55G. When using a UGF never use an air bubbler. ALWAYS use a power head. Not only will this allow the UGF to filter better, it also causes plenty of surface agitation.

Also, you said that you cleaned the HOB filter when you added the UGF. Did you rinse it in tap water or in the old aquarium water? By using tap water you would have killed off the beneficial bateria and thrown your tank into a mini cycle.

well they are back to hiding. It didn't last long but they are out more than they were earlier.

Sadly I rinsed the filter in the sink. I did not know about that. I have a lot to learn.

Thanks all for your help!

I shouldn't beat yourself up too much, you are certainly not alone in making these very common mistakes, now you have made them, you know what not to do next time. I can still picture myself cleaning media out under the tap when I first started.

You have chosen to keep one of the bigger and messier fish in our hobby. They do require a little more attention than your average guppy or tetra. Unfortunately you will not get away with using small tanks and inadequate filtration systems. I hate it when I see threads on forums where people are trying to suggest that it is possible to keep large fish in small environments, totally irresponsible in my opinion, these people know who they are.

i agree, im new to having oscars but i plan on keeping them. i have a 38 gal. right now and im gunna get a much bigger 1 soon but they are babies, i dont get y 2 2 inch oscars need 100 gallons right away. everone automatically thinks ur not fit to house them