Hi,
I have got two new Oscar Fish 4 days back. My tank is very big with some 700ltr of water and has two small angel fish, two silver dollar, one medium to big size parrot fish, four small parrot fish, two small to medium size texas and now two medium size oscar fish . Suddenly yesterday we noticed one of the oscar fish was lying on the floor of aquarium without much of activity, it is not able to swim and just has been on the base of the aquarium floor and i can even see the fish is extremely uncomfortable in breathing. For one minute i thought it was dead. it was just doing fine for the past two-three days i have no idea how to handle this and what could be the cause. we have separated this oscar from the other fish in the tank. could this be any of the following and if yes how can i treat the fish:

- Heat. it is very hot in Delhi and the aquarium temperature was almost 38degree yesterday untill i separated the fish into water with less temp

- Over feeding, but we did not notice the fish eating much or we putting in a lot of food for the past couple of days. ( Had the above two been the case it should have affected the other new oscar as well but the other one is doing just fine)

- Unable to adapt to the new environment

- I see the oscar throwing gravel from the mouth. Is it that it has swallowed some stones???

It is just not able to lift itself up from the ground, please help!!

Welcome to the community

You say your water temperature was 38°C. This is far too hot and could well be the cause of your oscars behaviour. The first thing you must always do if your fish start acting strangely if test your water for ammonia, nitrites, nitrates and PH. Until you give us the results of a water test its very difficult for us to help you. Finally, did you actually cycle your tank before getting your fish?

If waterparameters are correct, you could do daily waterchanges with waterconditioner added.
You can refill the tank with colder water, as long as you don't exceed 2 degrees of temp difference a day, for more that that may hurt your fish .
Turning off any lights may help drop the temperature too.
oh and wellcome to the site.

Thanks for the quick response. I am a beginner and have got my first ever aquarium some 6 months back. I had recently changed its 50% water and added fresh water. Also after noting the high temperature i changed with cold water. But sorry i do not know how to check for ammonia, nitrites, nitrates and PH. Can you please suggest some products or ways to do these tests??

and i do keep the lights off.. i don't know if that sounds funny but i have also been adding ice blocks in the water filter tanks below the aquarium to keep the water up to the desired temperature. Hope this will not cause any problem??

Thanks for all your help guys i really need it. i have not much knowledge of how to be a good guard for my fish. but i really want to keep all of them happy healthy and alive and am sure this forum will help me learn a lot more and succeed in what i want.

Thanks for being there.

hi if you go to your local pet store, im sure they will test your water for you, just take a test tube or smallclean tub, my petshop tests my water for nothing, or you can buy a test kit from the petstore, you can buy them on ebay aswell, hope this helps

Upasana wrote:


A master test set is very important, for fishstores often say the water is fine when quality is bad...just buy a set that has all 4 test we disired the results from.I ear API Seachem mentioned a lot but any LIQUID testingste will do.No strips, for they are less acurate.

Just another question, if you say you recently changed 50% water, i wonder how often do you change water and how much?
I change 50% of my water weekly to keep my fish healthy and happy.
Please beware that a difference between the old tankwater and the newly added water may hurt your fish.I advice not exceed 2 oC per waterchange, for bigger changes may shock your fish or cause disease.
lol, on the other hand i use those blue-freezer blocks from a coolbox, put those in a plactic bag and put them into the sump. but they hardly had any effect.
But i resolve to wc nowaday but only if the water reaches over 30oC and thats very rare in Holland.

Do you use decholrinator/Prime when refilling the tank with new water?

Thanks. i will go to the store and get the kit for myself or try eBay. Also, i do not change the water very often may be just once in month or so. Will make sure to change less % of water and often.

Yes i do put Anti-chlorine in the tank when changing water. Noddy; Whats wc??? is it the water chiller you are talking about??

Also, do we actually have fish doctors? I have never heard of one

Your tests will probably tell you to do more frequent waterchanges,wc that is.lol
Once a week 30% will often be the best option, but those test will help you out in deciding how much and how often.

hi and dont worry about the oscars picking up gravel, they will move it around to suit them, they wont swollow it xx

hey Upasana, any development???? i hope your fish can recover.
i suggest you add air stone to lower the temp... or lift the
discharge spray bar to agitate the water a little bit.

Hey Paul,

Thanks for the advise, but have been doing things to lower the temperature and it has gone low as well, but my Oscar is still the same, stuck on the surface...

Think i will just have to wait and watch