Tank Mates for Multis that will eat eggs/fry

[strobukm]

A bit of backstory... I have a 46 gallon bowfront tank that's been housing a multi colony for about 5 years. I started off with 4 F1 fish from a local store and 4 fish from a local fishkeeper's colony. In those 5 years, the colony had grown to at least 50-60 fish, but I've noticed a few fish have genetic deformities, probably due to inbreeding. See my other thread where this was discussed:
Is inbreeding a problem?

I decided to rehome all but a few healthy adults and whatever fry are currently in the tank and add a few new fish to introduce some genetic diversity. I won't rehome any of the deformed fish and I can't bring myself to euthanize them since aside from the deformities, they appear perfectly healthy, but I really don't want them breeding. Most, if not all of the deformed fish are male and there are probably 5-6 of them. I recently acquired a 36 gallon bowfront aquarium at a great price ($30 with the hood, light, filter, and heater!), so I'd like to move the deformed multis into that tank and add a few tank mates that would eat any eggs/fry just in case one of the deformed ones is female. What should I add? I've done some research and most people recommend a species-only tank for multis to enable breeding, but I specifically don't want these fish breeding.

 

[A201]

YoYo Loaches would likely take care of the unwanted fry.
My YoYo's do well in hard water w/
an 8.2 PH.

 

[MacZ]

YoYo Loaches would likely take care of the unwanted fry.
My YoYo's do well in hard water w/
an 8.2 PH.

Maybe, but they will just with their size stress out the multies a lot. They will rather just keep the multies from breeding but not eat the fry. At a price of some fully grown shellies eventually becoming sick. I also doubt that keeping loaches in a dedicated shellie tank is going to work. There is more than just the water parameters to tackle.

With shellies there is no other way than removing and rehoming surplus fish. It's like with algae eaters: Adding any fish for population control is not going to work out. Especially when the fish who's population has to be controlled are carnivorous aswell. The "control" fish will just get overly fat for a while and then just go for the food added. The "classic" for this job would be Altolamprologus and I have seen this happening a lot. Chunky Altos.

 

[FishDin]

The "classic" for this job would be Altolamprologus and I have seen this happening a lot. Chunky Altos.

Altos worked for me when trying to control the cyprochromis population, though cyp fry are basically sitting ducks. I think they kept the julidochromis in check too, but I never observed it.

They never got chunky, but perhaps there were not enough fry or too many altos.