Sorry for the delay replying.
Thanks everyone for all the positive comments
Here's the answers to some of the questions.
Tank is 84"(L) x 30"(W) x 24"(H)
Nitrate is about 40-60 with 35% water changes every other day.
Female motoro is 12" disc ...... minus what's been bitten off

Male motoro is 11"
Pinimas are 13" and 15"
Lemon fin barbs are in the region of 13"-15" long, around 5" high and over 2" thick! I dread to think how much they weigh! Lets just say I bought them by mistake when they were tiny and I was fairly new to fishkeeping..... that was 5 years ago.
I took the video at 9.30pm. The tank lights were on all evening so the rays didn't seem worried about mating in daylight.
Miles. You're more than welcome to embed the vid on your site. I'd be pleased if you did.
Oh, and the Barry White idea for music sounds good but I went for Cerys Matthews.
Cheers,
Nick.