Oscar slow growth over an 8 months period

Hi all,

I have a mainly Central American tank with a couple south Americans including an Oscar. All are still juveniles (under a year old).
I've had the Oscar for 8-9 months. Although was fairly small when I got him is still only about 5 inches or so, although quite solid and deep so well proportioned.
I've attached a photo, ignore the fact he is resting on the substrate, he just ate a big meal and the only chance to get a still photo of him, usually he is flying around the tank.

I expected an Oscar to grow quicker than that. Other inhabitants include silver dollars, salvini, green terror, red devil, JD, convicts, jaguars, vieja synspilum and a few elliot along with a large sailfin pleco.
At the moment, none of the cichlids are bigger than a third to half their full size (apart from the Vieja).

Interestingly I added the green terror later, was fairly small but quickly grew to the size of the oscar then slowed right down. The Vieja, added the same time as the oscar has grown from about 3 to 8+ inches in that time. The silver dollars have grown quickly, the red devil, added only a few months ago has already doubled in size and is now around 6-7 inches.
The JD's and salvini added the same time as the oscar are are actually not as big.

No aggression at all in the tank though....we not yet anyways.

All I can think of is this particular oscars genetics or the fact he doesn't really take to dry food much. I've not long started increasing his frozen food like frozen fish etc. Will see how that goes over time. He is a very aggressive eater for food he likes but ignores the dry food etc. Favourite food is live food like earth worms or lumps of frozen food.

Oh, the tank is 10 ft (330 gallons) which he has been in since the start.

 

He might be a she?

 

Tank is good. The thing is, these fish need to eat while they grow, you can feed them small feedings about what the tank eats in a minute every 4 hours. In order for them to grow they need to gain body mass and if you don't increase food/feedings to where they can take calories and put on mass growth stalls and they wind up small.

Competition for food is also a factor, but they will eat then poop and retain what they can and over and over and the idea is to keep putting weight on them and it will translate to faster growth, so food feedings need increasing and quantity fed needs increasing. And yeah some goes to waste and some becomes waste, so cleanings need to increase also.

It's how it's done to achieve maximum size and optimal growth, they are eating machines. And oscars are a prime example of a fish that if it doesn't get their nutritional needs met and winds up with HITH so if you are trying to avoid that and the scarring from it, and unfortunately many folks don't keep up with the feedings and they lack in size and health, a varied rounded diet that covers the nutritional bases is required for health and best coloration. If you want the orange to "pop" there needs to be more carotenoids in the diet ( orange pigment foods,,,carotene) this will get it brighter.

If it helps ideally for optimal growth they need about 3% of their body weight fed daily, and once they top out it gets cut back to .5-1% for maintaining body weight so they don't get fat. Not everyone is going to work out weight, most people just do frequent small feeding to keep food in them processing through.

 

Tank is good. The thing is, these fish need to eat while they grow, you can feed them small feedings about what the tank eats in a minute every 4 hours. In order for them to grow they need to gain body mass and if you don't increase food/feedings to where they can take calories and put on mass growth stalls and they wind up small.

Competition for food is also a factor, but they will eat then poop and retain what they can and over and over and the idea is to keep putting weight on them and it will translate to faster growth, so food feedings need increasing and quantity fed needs increasing. And yeah some goes to waste and some becomes waste, so cleanings need to increase also.

It's how it's done to achieve maximum size and optimal growth, they are eating machines. And oscars are a prime example of a fish that if it doesn't get their nutritional needs met and winds up with HITH so if you are trying to avoid that and the scarring from it, and unfortunately many folks don't keep up with the feedings and they lack in size and health, a varied rounded diet that covers the nutritional bases is required for health and best coloration. If you want the orange to "pop" there needs to be more carotenoids in the diet ( orange pigment foods,,,carotene) this will get it brighter.

If it helps ideally for optimal growth they need about 3% of their body weight fed daily, and once they top out it gets cut back to .5-1% for maintaining body weight so they don't get fat. Not everyone is going to work out weight, most people just do frequent small feeding to keep food in them processing through.

Thanks so much for your detailed reply. I think part of the problem was my mistake earlier in that he would and still eats some flake food but after a certain size that means little anyways and didn't eat pellet food etc. So the problem might have been as you mentioned, not getting enough consistent food over time. I have started to change that now but will be playing catchup for a bit. Even for blood worms or frozen brine shrimp, if scattered everywhere is not that interested compared to every other fish but if given in solid chunks he'll be the most aggressive. So for me, observe, adopt and learn.

 

Small meals more frequently gets the best results. I find larger meals can bind them up with constipation and slow their desire to eat, so eating until full will slow growth vs. Just enough, given more often to keep something in the machine to get nutrients off of constantly. Like foraging would work.

If you have space and another tank and don't mind guppy/minnow/ goldfish feeders you can buy in bulk and maybe work a discount and QT them, and then feed a couple here or there and he can forage and pick one off without dumping a ton of food that others will likely get. Big enough for him to eat, but maybe just a bit too big for the others to eat. This way there's fresh food basically at all times for him to gulp down. feeding them flakes or pellets will give the vitamins and the fish will give him good hits of protein and vitamins/amino acids ect.

Just another feeding strategy, if there's a lot of food competition and you don't want to go crazy dumping dry foods in there to make sure he gets enough.

The pellets if he'll eat them also size up and are pretty good at putting on weight and keeping up with optimal growth.

The hard part for everyone growing out fish is being mindful if it's too small or not enough, he won't get enough, and if too big he can't eat it, and finding the right size of food and quantity and quality so they can put on weight and keep growing. So many get set in a routine and the fish grows to a point and plateaus, and it isn't starved necessarily but instead malnourished.

I think flake is good for fry up to a couple inches, then getting him onto a quality cichlid pellet small size for 4"-6" or so, medium pellet for up to 10" and large pellet or stick for 10"+ as a staple food and supplement with bugbites, blood worms, chunks of shrimp or tilapia clams or mussels, if he'll eat it for protein. Earth worms crickets grasshoppers and bugs from the yard work too if he'll eat them. They can eat some fruits just no fruit seeds which can cause a blockage, in small amounts. Some veggie matter is good if you don't have plants to graze on.

Best of luck to you and your fish!

 

Small meals more frequently gets the best results. I find larger meals can bind them up with constipation and slow their desire to eat, so eating until full will slow growth vs. Just enough, given more often to keep something in the machine to get nutrients off of constantly. Like foraging would work.

If you have space and another tank and don't mind guppy/minnow/ goldfish feeders you can buy in bulk and maybe work a discount and QT them, and then feed a couple here or there and he can forage and pick one off without dumping a ton of food that others will likely get. Big enough for him to eat, but maybe just a bit too big for the others to eat. This way there's fresh food basically at all times for him to gulp down. feeding them flakes or pellets will give the vitamins and the fish will give him good hits of protein and vitamins/amino acids ect.

Just another feeding strategy, if there's a lot of food competition and you don't want to go crazy dumping dry foods in there to make sure he gets enough.

The pellets if he'll eat them also size up and are pretty good at putting on weight and keeping up with optimal growth.

The hard part for everyone growing out fish is being mindful if it's too small or not enough, he won't get enough, and if too big he can't eat it, and finding the right size of food and quantity and quality so they can put on weight and keep growing. So many get set in a routine and the fish grows to a point and plateaus, and it isn't starved necessarily but instead malnourished.

I think flake is good for fry up to a couple inches, then getting him onto a quality cichlid pellet small size for 4"-6" or so, medium pellet for up to 10" and large pellet or stick for 10"+ as a staple food and supplement with bugbites, blood worms, chunks of shrimp or tilapia clams or mussels, if he'll eat it for protein. Earth worms crickets grasshoppers and bugs from the yard work too if he'll eat them. They can eat some fruits just no fruit seeds which can cause a blockage, in small amounts. Some veggie matter is good if you don't have plants to graze on.

Best of luck to you and your fish!

Thanks so much again for your considered and amazing post.
I do have a bunch of other tanks including one which incidentally is overrun with guppies. I also have two spare 75 gallon 4 ft tanks not in use which I could potentially use 1 for that purpose too.

I will continue to try and feed the pellets. Most of the fish don't care too much for the pellets apart from the red devil which goes crazy over them. Maybe part of the reason why that one is growing so quick.

He will actually eat anything of size. Its almost the form of the food and/or texture...i guess like some humans haha. So he loves earth worms or good size bugs etc so yes I'll keep that in mind and do some more foraging in the yard/bush.

In essence, as you've described, a good varied, consistent diet that suits them

 

Pics of tank for those of us with just little 180 gallon tanks would be cool~!

 

Ok my 2 cents . Oscar’s are solitary fish. Not too aggressive at feeding time. The fish you have him with could also be stifling his growth. Might be best to move him into a 75g by himself. They are very personal fish. By itself its personality should show. By itself it will grow. I’m from a bygone era where all we fed our Oscar’s were feeder goldfish. Mine would eat 6 in a feeding. I’d feed twice a week. He grew to about 10” in a 55g and lived over 5 yrs (I was a kid).

 

Pics of tank for those of us with just little 180 gallon tanks would be cool~!

No worries will do. I can't seem to get a good shot of the whole tank in one shot but I'll take a few and post here

Ok my 2 cents . Oscar’s are solitary fish. Not too aggressive at feeding time. The fish you have him with could also be stifling his growth. Might be best to move him into a 75g by himself. They are very personal fish. By itself its personality should show. By itself it will grow. I’m from a bygone era where all we fed our Oscar’s were feeder goldfish. Mine would eat 6 in a feeding. I’d feed twice a week. He grew to about 10” in a 55g and lived over 5 yrs (I was a kid).

Thanks for your reply.
This Oscar seems to operate at two extremes at feeding time. I was showing a neighbour when feeding pellets and could see the Oscar wasn't even interested. Then a few days later he was seeing me feed again, this time pieces of fish fillets and the oscar was literally jumping out of the water and my neighbour couldn't believe the contrast. Is extremely aggressive when offered favoured foods but not otherwise.
I do notice now that I have upped the protein and him eating more that he is just starting to increase in size a bit so will see how it goes.

Sometimes techniques from the bygone error still hold true today though. I guess back in the day you did what worked and weren't influenced by all the media and youtube etc today.

I am thinking of putting into process the guppy version of your gold fish feeding though and as they are bred by myself I know they are good.

I do have the option also as you mentioned of using one of my spare 75G tanks as the solo inhabitant. Will see how it goes over the next month or two.

 

See some photos as promised. Apologies for very ordinary (read dirty) glass. It was cleaned later after i saw how bad it was. But you get the point. Oh I forgot to mention I had a few clown loaches. They are actually relatively small, they look bigger in the pic than they are. Good clean up crew though.

Oh the coral rocks aren't in their for decoration, its to increase the ph, which was sitting around 6.4 for a long time till I realised, now stable at 7.2, same as out of the tap.