6 Adult Oscars in a 100 Gallon Tank

[Vibsee]

I currently have 6 adult Oscars in a 100 gallon tank. They have been there for about 5 months now. I have been performing a 30% water change everyday with about 60% on weekends. They were size 7 - 7.5 when I got them.. Now they are about 9-10 inches each. I intend to keep them in the tank for another 4 months.
Readings in the tank.
Ammonia - ZERO.
Nitrates - 10-20.
I posted this on another forum and was advised to come down to 1 oscar in the tank. So I have upped the water changes to almost 50% daily till I get my next 100 gall after 4 months.
All the fish are healthy, not aggressive, eating well and swimming around minding their own business.
One pair is in the process of mating I think.
Any thoughts?

 

[Lepisosteus]

Keep the pair sell 4. 6 is way to many

 

[Vibsee]

Keep the pair sell 4. 6 is way to many

There is one more breeding pair amongst the six. I'm planning to split them up and keep 3 each in two tanks. But that will only happen in March or April. My question is... why is six too much? If the water readings are normal, with daily water changes and if the fish are healthy and doing just fine.

 

[SandNukka15]

There is one more breeding pair amongst the six. I'm planning to split them up and keep 3 each in two tanks. But that will only happen in March or April. My question is... why is six too much? If the water readings are normal, with daily water changes and if the fish are healthy and doing just fine.

Although u may be doing well with keeping the water clean oscars can get pretty big and space wise you wont be able to house all 6 in that tank

 

[Binge]

The big concern with oscars is aggression then bio load.

Why they are telling you 6 is to many is because they like their space. without it you get extra aggression. Now your throwing breeding into the mix which causes a whole new bonus level of aggression.

While you are okay right now at some point (likely soon since you have pairs) one of them will likely be hurt or killed.

I applaud you keeping the water parameters in check doing daily water changes gets tiresome. Those extra water changes may also trigger more breeding behavior hence more aggression.

People are just trying to save you potential heartache of lost or injured fish.

In the end however they are your fish if it is worth the risk to you to wait the 3 months till you have the other tank it is your call. Do however continue to keep a close eye on water parameters and aggression. Perhaps grab some kind of cheap rubber maid tubs as a back up plan for individual fish In a pinch till you get your other tank.

I would say two per tank in the end is your best bet however.

Good luck.

 

[Vibsee]

Those extra water changes may also trigger more breeding behavior ??!!!! This.. I wasn't aware of.. well as of now 2 tigers have gone in one corner.. where I've kept a tile for them.. they just hang in there, clean the tile and defend that corner.. 2 mosaics who have already bred hang around together.. It's the 2 Lutinos who are kind of lost.. They keep wandering into the tigers corner and keep getting pushed back... and the water changes are tiresome but provide good early morning exercise.. .. anyways I'm trying to get my hands on the python siphon.. will make it way easier I feel.. and yes.. I have a 30 gall ready.. just in case.. One question.. are these guys capable of fighting in the night when the lights are out and it's almost pitch dark? coz thats the only time when nobody in the house has an eye on them.

 

[ehh]

It's a little cramped don't you think? Water quality a side. Which, btw, is pretty awesome you keeping up to par.
There's more to keeping fish than water quality. Yeah it's nice the water is clean but those oscars don't want to be in a cramped tank like that. That's why that tank is over stocked.

 

[Frank Castle]

Those extra water changes may also trigger more breeding behavior ??!!!! This.. I wasn't aware of.. well as of now 2 tigers have gone in one corner.. where I've kept a tile for them.. they just hang in there, clean the tile and defend that corner.. 2 mosaics who have already bred hang around together.. It's the 2 Lutinos who are kind of lost.. They keep wandering into the tigers corner and keep getting pushed back... and the water changes are tiresome but provide good early morning exercise.. .. anyways I'm trying to get my hands on the python siphon.. will make it way easier I feel.. and yes.. I have a 30 gall ready.. just in case.. One question.. are these guys capable of fighting in the night when the lights are out and it's almost pitch dark? coz thats the only time when nobody in the house has an eye on them.

yes, some fish by nature spawn after a rainfall - and often drought precedes rainfall - and they will not likely breed during a drought so they breed while the time is right. Draining the water down and doing a WC is about as close to a rainfall in captivity as it gets......the only better way is allow LOTS of evaporation to actually simulate a drought rather than draining thee water yourself. I did a WC on a few tanks last night and I just noticed an egg-covered clamshell from my pair of Cichlasoma cienagae a few minutes ago. Every WC they spawn like clockwork.

As far as the Oscars go, 1 pair per tank is always best w/ any breeding pair. I have several tanks for community cichlids and several just for breeding pairs w/ fry and nothing else. My friend had 4 adult Osccars in a 75g along w/ some Convicts, a JD, catfish etc, now there's nothing but a catfish left.

What are tank dimensions and what type of filtration do you have?

 

[Vibsee]

Tank dimensions in inches - 60*16*24 ... filtration is the overhead filtration that came with the tank.. A sunsun 304 external canister and a bio sponge..

My question again... if anyone knows.. Are adult Oscars capable of fighting in the night when the lights are out and it's almost pitch dark? Or do they retreat in their corners and wait till morning?

 

[Frank Castle]

Tank dimensions in inches - 60*16*24 ... filtration is the overhead filtration that came with the tank.. A sunsun 304 external canister and a bio sponge..

My question again... if anyone knows.. Are adult Oscars capable of fighting in the night when the lights are out and it's almost pitch dark? Or do they retreat in their corners and wait till morning?

Most cichlids (besides Cyphotilapia frontosa) are diurnal, meaning they are active during the day.

Fish have no eyelids therefore when lights go out they see this as the natural pattern of the Sun and take advantage of the dark by sleeping.

Unless your fish experiences less than 12-15 hours of light per day, they should remain inactive and asleep during darkness hours.

I doubt there is any fighting in your tank at night unless you have nocturnal species for I have species 10x more aggressive than you and I have no issues in my tanks at night.


Don't take my word as a guaranteed, but this is just IME. You should be ok at night as long as daylight/windows/etc doesn't wake them up before you do