my oscar is 2 in long had him for 4 weeks in a 10 gallon tank to make sure he was all good for the main tank.every thing was really great until yesterday morn i saw what looked like clear stool he lays in his little house and does not eat. my tank i now is small but he was going in a 100 gall for himself.the 10 gall get 50% water change every day ,has plenty of air flow and a blue lite which now when i turn on if he is swiming around will hide in his little house. the 10 gall also has no amm,nitrite,and nitrate, levels at all.i clean this tank out evey time i get a new fish to make sure nothing may be still in it.now the only thing i did diff was had a second oscar 2 days ago that was in a cycled tank for 2 months and it got a leak and i needed a place to put it.i fig that the one thats been in the 10 gal for 4 weeks was all good but now this happened. the frist day they swam together the next day i got this prom. please help i love oscars and never had a prom. before. im treating the tank with pimefix .thak you

hey there and welcome!
Your o's are suffering from too little space to live.
With a good working filter nitrates should be present.
do you have a filter and is the big tank cycled with fish in it?
If the tank is cycled, please transfer the oscars as soon as possible.
They are not gonna survive in the 10Gl for long.
Your 50% wc daily may have saved them so far.
Do you use Prime/ waterconditioner with all those waterchanges?

yes the big tank is cycled has been for 6m it is also 100gal and has a 10gal sump .yes i treat the tank after every water change. i will transfar the fish but the way the one is acting and the clear stool i was told it maybe stress but i still feel treating is good to make sure

then you still may need some extra filtration.
A sump should contain at least 25% of the whole tanks volume.Ii use a 50Gl sump for a 180Gl tank.
then finish the whole treatment and transfer the fish then, at the same time with your old filter.

thank you ill give it a try

If i get this right you added another oscar and now the original one is hiding. This oscar may be hiding due to bullying or sulking

You cant have zero nitrate, nitrite and ammonia is a cycled tank, please re test with the bottle type- not the strips. Please read the section on the homepage about cycling, i suspect your tank isnt cycled and as noddy said the water changes has saved your oscar so far

Add your oscars to the big tank now even if it isnt cycled- this will help with any ammonia and nitrite levels. It will also reduce any bullying as they will have more space to themselves

the tank they are in is not yes thats why all 0.the 100 gal is cycled thats were they are going.just making sure the fish were good before they go in.

Have you got any fish in the big tank?

i had 3 jds in the 100 until i got them a bigger tank now my o's are going in the 100

How long has the 100 gallon tank been empty, and if so, have you kept it running all the time?

yes it has been running for 1 year and empty for the 3 weeks and i kept it going just kept puting fish food in it everyday just to be safe .i tested the water im little worried about the ph its 7.2

7.2 is totally fine. In my opinion anyway