Lemon tetras spawning or aggressive behavoir?

[Cleggat]

So I originally had a group of 6 lemon tetras, due to new fish coming in without QT 3 were knocked out in the past year or so. So two days ago I added another 3 lemon tetras and 6 pretty tetras, all was going great they all grouped together. This was until last night one of my original ones, the darkest and biggest decided to chase the smallest one, he chases it around and then stretches out his fins 'dancing' infront of the other one. But now at least 2 or 3 of them are chasing the others around then rubbing their body against the other. They are on frozen foods at the moment, 25c and water ppms are good just slightly acidic, here's some videos and thanks in advance!

 

[Cleggat]

So I took the grass out and shook it in a breeder net.. Tiny little circles came out which are light tan and are soft so it's not my gravel, still if anyone can confirm this is them breeding I would be pleased? I have switched the lights off since the eggs don't like light, the gbr was going crazy at the grass trying to get in and nipping at it and over at my other plant which they were shaking at my cories are now going crazy..

 

[Cleggat]

Also just found out that they hatch within 20-30 hours, any info would be greatly appreciated! I am putting java moss in the breeder net once I get home and shall look into egg yolk for feeding (any tips on this would be great too)