i would be embarassed to post pics of my set up, it is the uglyest i have ever seen.
The set up is mainly rocks, slate,caves and som wood.
2 external pumps and one internal, a total turnover about 12-15 times.
In the beginning i tried everything to get them going, but nothing happend.
After about 1.5 years i sold out 4 males and bought 9 new ones, not actually knowing what gender they where. I now have 11 zebras.
I think i have 4-5 females and 6-7 males.
I left them alone for about 2 months, put up a curtain in front of the tank so they could have a little peace, and was a little neverminded about the whole ting.
I was a bit lacy with the water changing altso, and when i after nearly a month decided to change water, i spotted the female in the males cave for the first time. And since that they have been going constantly.
I feed them mainly frosen bloodworms and tetrabits(diskus)
If you want a pic of the set up just mail me
[email protected]
Regards
Tom
. Personally I would try to give him a break just incase he burns himself out. You might want to stop stimulating spawns for a while so that he gets a rest. If he is spending a lot of time in his cave which he obviously is then he may not be getting enough food/recovery time. That's a hell of a lot of spawns since January, perhaps he knows that zebras are endangered and he is trying to do his bit to preserve his kind 
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