I don’t know about how difficult it is to get Otos to spawn? I have lots of them!
Here are my recommendations:
You need at least six fish preferably more.
A well planted tank with driftwood
Very soft water KH 2-4 deg
pH vary between 6.5 – 7.8
Temp 79F
Lots of algae preferably brown surface algae which they eat first.
Set your tank up pH 7.8 KH 4 and get it green.
Add Otos
After they acclimate change water (5-10% a day) using RO and CO2 bringing pH down.
After about 2 weeks the fish will become very active at first at night and then during the daytime. At first the fish will dart around the tank by themselves. Eventually you will notice one fish chasing another. At this point you will begin to distinguish the sexes. The female will have a larger abdomen, the male slimmer.
Eventually you will see two or three males chasing a female around the tank.
When the female stops usually on the underside of a leaf, one of the males will mount her. Here is a picture of what it looks like:
http://www.otocinclus.com/breeding.html
They stay this way for some time maybe as long as 15 sec.
When the male get off the female moves on and 3-4 eggs will be on the underside of the leaf.
If you want to save the eggs cut off the leaf and transfer it to another tank or a fry net.
The eggs hatch in 48 hours at 79F
They are free swimming in another 48 hours.
I feed them algae from the drift wood and bits of algae pellets.
Here is someone else who is successful:
http://www.planetcatfish.com/forum/v...ic.php?t=16816
Actually Otos are really prolific. I have eggs all over my community tank and they breed side by side with my neon tetras.