Hey Basstian -- congrats!!!!
I would recommend that you try to leave the parents alone --- they may just be newbie parents. If they are breeding for you, you've got the right set up and parameters. They'll continue to do so regularly.
The issue with leaving the fry with the parents for an extended period of time is that the BG fry will outcompete the weaker EB fry ... and in the end, you won't get any EB fry.
I've raised dozens of BGxEB combos. This is my process:
1. Eggs hatch - leave with parents. Takes 3 days.
2. Wigglers - leave with parents for 2 days.
3. At the third wiggler day, they are just about to go free swimming ... this is when I strip the fry.
4. I wait until night time, the female will have placed the fry in a cave (best to have supplied caves for her to move fry)
5. 1-2 hours after the lights go out and the fish are asleep, I take the cave out and move the wigglers to a prepped holding tank.
6. The holding tank is usually a 20 gallon with a heater, seasoned sponge filer and one small bristle nose pleco (1.5 inch to 2 inches)
7. The fry will start to become free swimming in the next 24-48 hours--- once this happens , you must have live baby brine shrimp at the ready and feed twice a day.
8. At 3-4 weeks, you will be able to identify the EB from the BG fry, by 1 month you will need to separate the BG from the EB fry.
9. I feed heavily in the first month, at least twice a day. On weekends, I try to feed 3-4 times a day. Water changes are extremely important during this time period.
What else do you have in the tank with the EBxBG pair? If you have a lot of other fish ... and they can't protect the spawn, they'll just eat em.
Hope that helps.
~Yankeejack