good seeds but no sprout

hi am a guy from bulgaria i buy some seeds from a seedbank .I buy a Heated Propagator and Rockwool Cubes my be i can get some good job but for noting .
i can crack the seeds in 1 day sow that means the seeds are good i buy BLUEBERRY seeds . i get the Rockwool and i let them in water till thay go down in water.The P/H of the water is 5.9 and my temperatue is from 25 to 30 .
sow i tink is good. after i get the seed and i put them in Rockwool i put them in the Heated Propagator but to day i see that the seeds are in the same way that i put them 5 days pass WITH THE SEEDS I SEE SOME WHITE COLER NOW BUT IS NOT THE ROOT
W DO U TINK ?
AND w is the best seeds that i cn buy for a beginner ?

may be u can tell me w am doing rong
thanks for yor help from be for

 

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