Can I expect any passive breeding?

[DavidMoss]

I’m setting up an acrylic clarity plus 26 gallon half hex tank. The fish I plan to house are some clown killifish, rosy loach, a pair of super bristlenose pleco. The plan is to have it heavily planted tank in an island type of layout for a the fry to hide and will be trying to fill most of the back with some jungle Val. I also thought about adding a school of CPDs but I’m not sure if that will over stock the tank with any babies that might survive if any. I’m still growing plants while I get the fish together and start to grown them out.

[Beardedbillygoat1975]

Clown killis and CPDs have very low bioloads. Loaches are egg thieves and very inquisitive so breeding with them present is not always best or easy. Corys may be a better choice dwarves would be good as their mouths are so small. BNPs are also sometimes opportunistic feeders I’ve had them eat Cory eggs. With clowns and CPDs you could do a herd of Neocaridina.

[gardenman]

By and large, any pair of fish in a tank will breed given the opportunity. It's what they do. Getting fry to survive is where things get tricky. Bigger fish eat smaller fish and fry are smaller fish and prone to getting eaten. Pretty much everything eats fish eggs, even the fish laying the eggs will often stop mid-laying and swim down to munch on a few of the eggs they've just laid. (And frankly, it's good that everything eats fish eggs, or we'd all be knee-deep in fish. A large koi can lay millions of eggs.) I wouldn't worry about overstocking the tank with fry that survive as fry create a minimal bioload and grow slowly enough that any that survive will likely have the bacteria in the tank growing with them and keeping pace with their waste output. My tanks are all horrifically overstocked by any common measure, but they all became stocked with fry, so the bio filtration kept pace with the fish.