discus wanna hatch

even i keep swapping boyfriend for female discus the result is white egg after 2 day = ( . may be temptures is way too high . i switch on 30 - 31 .. hopefully will hatch one day = ( .

infertile? what can i do make the egg hatch ? tempeture should be 30 or 31 ? PH any changes? anything i can do make it fertile? let me know .. thanks........ = )

i have bought 2 pair been waiting so long finally lay many eggs but always turn white after 2 days.. anything do with the ph? i doin it on 6.5 -6.3 . temp - 30 . Is there anything more I should look out for?