Just for my curiosity are any of the black/white pleco you own 'out going' or seen around the tank during the day. I know it comes down to individual fishes as well as species but curious if I were to add one to a display tank which species I would try. I have experience with several species of pleco and have found that sex of the fish as well as individual behavior makes a difference in their behavior but generally speaking some species are more shy (or nocturnal) than others.
When I was outputting them at their maxi rate I was selling them at $100/inch. Ultimately, I sold lowered the price by offering the first 1/4 inch for free. As to how much I made that is a relative question. I have owned zebras since about 2003 but breeding was not until 06. I think they are a striking looking fish. Pure white and pure black in world of colors.
Back then I was lucky to be able to buy them and had to spend $270/fish and 5 fry were free. That was $3,510. That did not include the hours spent driving an hour+ each way to see them and then to pick them up. It doesn't count the cost of the tank and contents, the food and electricity, etc. It also doesn't count the fact that the Belo Monte dam may likely wipe them out in wild. It also doesn't count the risk that for any reason one can lose a fish. And it doesn't count the cost of the penalty I had to pay to take a premature withdrawal from my IRA to pay for them.
Next, they do not spawn non stop. The best you can theoretically get from just a pair would be a dozen spawns a year. And the average number of eggs that hatch and that you can expect to sell is 12-15. So you are looking at 144 to 180. But I used to assume 10-12 per spawn so 120 - 144. But they tend to spawn for about 9+ months and then hiatus for about 3+. So you can expect about 108 to 135.
To sell them you will have to ship. My rule was I would not sell them until they had both reached 6 months old and 1.5 inches total length. So you have to feed and house them for that. You have to keep them alive, healthy and growing. You cannot do this on flake or dry sinking foods. Diet matters both for spawning the adults and for feeding the kids.
Today they still sell for $100/inch or a bit more, but not from stores etc. So you can figure out about what one might make from a pair.
If you want to give them a try the safest thing to do is to buy a small group of youngsters. the cost/fish will be less. At a smaller size they are difficult to sex, So the odds are if you buy at least 6, you will for sure get a couple of females. I work with groups not pairs. I feel 6 is the absolute minimum, but I prefer 8 and normally 15 the max. Not pushing things expect it to take between 2 and 3 years if you start with 1.5 inch fish.
The thing about all of this is no matter how well one cares for a pair, no matter how well they are fed, it is still possible to lose one, especially if they are not in their own tank with nothing else that might carry something nasty. But if you did lose one, then all you have is a lovely fish you will rarely see. If you want to work with pairs then you either buy even more and when they get bigger you may be able to vent them and know for sure. or you can try to catch a trapping and pull them both in the cave. But one pair has that added risk if is is all you have for breeding.
I am now in my 70s and working my way out of the hobby over 2022 and 2023. As a result a while back I stopped buying fish I needed to grow for very long before they were potentially able to spawn. You sound a lot younger and can be patient.
As for what I made, mostly it went to pay my hobby costs and then to pay for the next species I got. The price got a lot more than zebras as I moved from expensive to insane But I am a sucker for the B&W Hypancistrus: zebra, L450, contradens, L173b, L236, L173 and my fianl buy, L236 superwhite.Along the way I had addorted tank strains of bn plus P. compta (leopard frog pleco).
Hi, my name is TwoTankAmin and I am an aquaholic.........
I bought proven breeders and I had my first spawn within two weeks of getting them home. I was lucky. There are some real experts who cannot get them to spawn. They had to just ignore them for a year or two and then out of the blue.... I am fortunate, I have great well water for SA fish abd other soter water , near neutral pH fish. Every pleco I have kept has spawned sooner or later. So did angels, corys, danios, blue eyed rainbows betta imbellis and a few others.