Tank Stock

[Zachk29]

So my friend had two juvenile tiger Oscars in his tank but one of his seals started to leak. So i told him I would take care of them for him because he didn't have anywhere else to put them. He isn't sure if he is going to re seal or buy a new fish tank or maybe give up on having fish until he gets his own place. My question is I already have three firemouths, 1 albino tiger oscar, severum, and a bristlenose pleco. How overstocked is my tank now with the extra two oscars. The tank is a 120 gallon, also what percent water change should I do weekly. Will this stock have any chance when they are full grown or will I have to remove fish if my friend can't take them back?

 

[Zachk29]

Actually its more like a 130 gallon 72 inches length, 23 inches tall, 18 inch width.

 

[xDestro]

Imo 2 Oscar's would be pushing that tank.. Of course everything depends on the size of the fish... If everyone gets a long I would definitely up your water changes and maybe upgrade filtration depending on how long you will be keeping them

 

[Covetous]

This may be the unpopular opinion, but I think you’ll be fine. Don’t slack on your water changes though. Definitely stick to a weekly large water change or bi-weekly smaller ones.

I kept my two Oscars in that exact size tank for a couple years ( they where already full grown) along with a very large severum, a common pleco that was too big to turn around (he went into my pond eventually) and various other tank inhabitants that grew fairly large. Some worked, some didn’t. Eventually I felt I wanted a larger tank and upgraded to a 180. But I think 3 Oscars will be just fine for a long while in the 125.

Now if THEY decide there isn’t enough room and start beating on each other. Well, then it won’t work. Trial and error. Good luck!

 

[Zachk29]

I’m thinking a solid 40-50% water change a week. I’m hoping my friend decides to get another tank and takes his two oscars back but if not I might be stuck with them if it works out with my current fish and if it’s not to crowded when they grow up. I have a fluval fx6 for filtration.

 

[ryansmith83]

If the Oscars are large I would recommend more than 50% a week. Large fish are heavy bioload fish and Oscars are prone to HITH it their water quality is poor.

 

[Rocksor]

I’m thinking a solid 40-50% water change a week. I’m hoping my friend decides to get another tank and takes his two oscars back but if not I might be stuck with them if it works out with my current fish and if it’s not to crowded when they grow up. I have a fluval fx6 for filtration.

Don't rely on a percentage. Start testing your nitrates everyday for the next couple of months after you add your friend's oscars, and do a 50% water change once you see it hit 10ppm (assuming you have 0ppm nitrates out of tap). If you can't keep up with keeping the nitrates below 10ppm, then it is time to start rehoming some of the fish.

In the long run, you will easily need to bring the water level of your tank down to the top of your tallest fish's dorsal every 2-3 days with that bioload just to keep the nitrates low.