Need to move an aggressive black molly. Suggestions?

[alenelap]

Hello all!

Short back story: Ages and ages ago, I knew my way around an aquarium, but then the kids came and the fish fell by the wayside. So I feel like I am relearning all this.

For the past 8 years, we've had one lone common goldfish in a 10 gallon tank. He died about two weeks, and my oldest daughter went out and bought four new fish for the tank on Saturday.

• Another common goldfish (I assume -- looks like a goldfish but with coloring I've never seen before)
• A pictus catfish
• A plecostomus
• A male black molly

So yes, this tank is overcrowded. The immediate problem is the black molly which is mercilessly picking on the goldfish.

I'm going to go buy a new tank for the molly and am wondering if he'll be fine in a 10 gallon tank alone or if I should try to get something bigger that can house the catfish as well. The smaller tank would work better in our house but, of course, I know bigger is always better for the fish when it comes to tanks.

Speaking the catfish, we made the mistake of trying to net him out of his bag and one his fins got caught. We cut him out and now he's swimming around with a bit of netting attached to him. How concerned should I be about that?

Thanks so much for any wisdom you can share!

 

[King Fisher]

If you are going to get another tank but are tight on room I'd get a 20g long. Keep the Molly in the 10g and the goldfish and pictus in the 20g long.

 

[alenelap]

If you are going to get another tank but are tight on room I'd get a 20g long. Keep the Molly in the 10g and the goldfish and pictus in the 20g long.

Oh, that's a good idea! Thanks!

 

[King Fisher]

Your next problem is housing a pictus catfish and a goldfish due to recommended water temps. Goldfish shouldn't be in water over 72 degrees for extended periods of time. A pictus catfish shouldn't be under 71 degrees for extended periods of time. So your target temp is 71 to 72 degrees consistently. I'd air on the side of the goldfish and keep it at 71 degrees as catfish are a tougher fish IMO. Your Molly definitely can't go with your goldfish as a Molly needs temps of 77-84 degree water. Now you could add the Molly and pictus together and they could both enjoy a tank temp of 77-78 degrees.....if the Molly doesn't try to harass him.....but now you got a common goldfish in a 10 gallon which is to small. If you put the Molly and the catfish together in the 10 gallon it's to small for the catfish and arguably the Molly as well. Essentially that 10 gallon is to small for the kind of fish you have. You are also trying to mix tropical fish with a goldfish (not tropical). Personally I'd use the 10 gallon as a quarantine tank in case you need to remove a sick fish for treatment or if you obtain a new fish and you want to QT it for observation. Get yourself two 20 gallon long tanks if you can spare the room. Put the goldfish in one 20g by itself and put the Molly and catfish in the other 20g. You could actually add more Molly's or other schooling fish in that set up.

I just read you had a pleco which I'd put with the goldfish because they can stand temps as low as 60 degrees. You could put your goldfish in comfortable water temps with him. Again, depending on the type of pleco it's another large fish for even a 20g long. If it's a common pleco.... return it to the store. You will be doing that anyways in a year or two.

 

[alenelap]

Yes, this combination of fish is a bit of a mess, isn't it?

I think I need to find a dedicated pet store or start shopping online for supplies. The only heaters our local big box store have are preset to 78 degrees and can't be adjusted. That's actually the type of heater that has been in the tank for the last 8 years with our old goldfish, but it seems to keep the temps in the low 70s according to the tank thermometer. Maybe that's why the old goldfish did so well for so long.

Last night, I went to the store to see about getting a divider to add to the 10g tank to separate out the molly, but they didn't have any. I ended up picking up a 3 gallon tank to quarantine the molly for now. The goldfish wasn't looking so hot yesterday, and I was slightly worried he wouldn't make it through the night with the molly constantly picking at him. I know the 3 gallon tank isn't a permanent solution, but hopefully it buys me some time to figure out what to do with these fish.

If I can find space for two 20g tanks, that's probably the way to go if for no other reason than I get a bit stressed about trying to keep the water quality decent in a 10g.

And then just so I'm not totally off-base, I've attached a photo of the mystery fish. This is a goldfish, right? My daughter said it was in a tank with tropical fish but it looks like a carp to me.

 

[King Fisher]

Looks like an unlucky one that didn't change to orange

 

[goatnad]

Yes, this combination of fish is a bit of a mess, isn't it?

I think I need to find a dedicated pet store or start shopping online for supplies. The only heaters our local big box store have are preset to 78 degrees and can't be adjusted. That's actually the type of heater that has been in the tank for the last 8 years with our old goldfish, but it seems to keep the temps in the low 70s according to the tank thermometer. Maybe that's why the old goldfish did so well for so long.

Last night, I went to the store to see about getting a divider to add to the 10g tank to separate out the molly, but they didn't have any. I ended up picking up a 3 gallon tank to quarantine the molly for now. The goldfish wasn't looking so hot yesterday, and I was slightly worried he wouldn't make it through the night with the molly constantly picking at him. I know the 3 gallon tank isn't a permanent solution, but hopefully it buys me some time to figure out what to do with these fish.

If I can find space for two 20g tanks, that's probably the way to go if for no other reason than I get a bit stressed about trying to keep the water quality decent in a 10g.

And then just so I'm not totally off-base, I've attached a photo of the mystery fish. This is a goldfish, right? My daughter said it was in a tank with tropical fish but it looks like a carp to me.

im not great at telling them apart either but i do know koi have barbels around their mouth and chin and goldfish do not. also goldfish are a type of carp. does your fish have them?

 

[D-Fish]

Yes, this combination of fish is a bit of a mess, isn't it?

I think I need to find a dedicated pet store or start shopping online for supplies. The only heaters our local big box store have are preset to 78 degrees and can't be adjusted. That's actually the type of heater that has been in the tank for the last 8 years with our old goldfish, but it seems to keep the temps in the low 70s according to the tank thermometer. Maybe that's why the old goldfish did so well for so long.

Last night, I went to the store to see about getting a divider to add to the 10g tank to separate out the molly, but they didn't have any. I ended up picking up a 3 gallon tank to quarantine the molly for now. The goldfish wasn't looking so hot yesterday, and I was slightly worried he wouldn't make it through the night with the molly constantly picking at him. I know the 3 gallon tank isn't a permanent solution, but hopefully it buys me some time to figure out what to do with these fish.

If I can find space for two 20g tanks, that's probably the way to go if for no other reason than I get a bit stressed about trying to keep the water quality decent in a 10g.

And then just so I'm not totally off-base, I've attached a photo of the mystery fish. This is a goldfish, right? My daughter said it was in a tank with tropical fish but it looks like a carp to me.

Koi
You can tell by the number of rays in the dorsal fan as well as the shape of the head at mouth.
Actually looks nice and healthy and would make a nice fish if you have a pond for it.

 

[alenelap]

Koi? Well, there's something I know zero about. I'm guessing a 10 gallon tank definitely won't do for him then.

From what I can tell, he does have barbels. This photo was taken on Sunday right after we got him. Yesterday, he started lying under an arch rock we have in the tank. We figured he was hunkering down there because he just fits in the space and the molly could only get at his tail when he was there.

Now that the molly is out, we were hoping he would come out but he's still under there. My daughter is beside herself thinking he is going to die. However, I turned off the tank light about an hour ago, and I noticed he is out now...at least until I get close and then he scoots back under the rock. So here's to hoping he's just timid and not ill or hurt.

 

[Taiken5968]

Goldfish get pretty darn big, and shouldnt have ever been in a 10g. You probably need something bigger than a 20. I'd say a 30 at the very least.


I'd put the pictus, and the Molly in a 20 long,assuming their temp requirements are close, but wouldn't put much else. I wouldn't worry about the Molly picking on the pictus. Pictus cats are pretty active and rambunctious. They get a decent size too. Some places say 6 some say more. Some say you need a much bigger tank for the pictus, but I think it could work with good water changes, and no additions.

For alot of good information on goldfish, look up aquarium co-op on YouTube. He is a goldfish nut.

 

[King Fisher]

Honestly, turn in the koi and pleco, if it's a common pleco, to your local LFS. Get you a 20g long and put the catfish and Molly in it. Stash the 10 gallon for a quarantine tank. You could add some more Molly's to that 20 or go with a school of small fish like tetras, danios, ect... Just keep good filtration, once a week 50% water changes with a gravel vac and you should be good. I've kept a pictus in a 29g before. He rarely moved out of his cave except at night. I don't believe they need a large tank from my experience.

 

[alenelap]

Thanks all for the feedback.

Poor molly didn't make it. He was looking great yesterday too. :-(

Going to go shopping for a bigger tank this weekend and figure out what to do with the other fish.

 

[King Fisher]

Sorry to hear that